Police in Portland and three neighboring towns who are investigating six armed robberies in six days believe there is a connection between the unusual cluster of potentially dangerous crimes targeting small businesses.

Another armed robbery occurred at a Subway in Westbrook on Monday night, and police are expected to investigate whether it is linked to the previous six holdups.

Police have not definitively said that the six robberies were committed by the same person, but investigators are proceeding as if they may be linked, and have warned the public not to confront the robber. In each case, a man with a similar description and wearing a mask showed a handgun and demanded money.

“It’s a desperate person who will more than likely continue to do what he’s doing,” said Portland police Lt. Robert Martin. “Eventually, something is going to happen and it’s going to be a dangerous situation, an armed encounter between law enforcement and the subject, or some type of encounter between a citizen and the subject. And we don’t want to see that happen.”

The departments are pooling resources and detectives are asking the public to help by scouring private home or business surveillance systems that may have captured images of the robberies showing the suspect and any vehicle that may have been involved.

The robberies were reported in Portland, Westbrook, Falmouth and Cumberland starting March 20. No one has been hurt.

And then there was the robbery at the Subway on Route 302 in Westbrook Monday night.

Reached by phone, restaurant manager Kerri Consiglio said a man whose face was covered entered the sandwich shop at around 8:34 p.m. and demanded that an employee open up the cash drawer. The robber had a handgun in his waistband, but never pointed it at the worker or threatened the employee, Consiglio said.

The robber ran away with just over $200 in cash, she said.

“He was slightly more talkative than you would expect. He told my employee to keep the change after he emptied the cash drawer,” she said.

Police in Westbrook weren’t available Monday night to say whether they believe the robbery at the Subway is connected to the six previous holdups.

Police in Portland have stepped up patrols around convenience stores and other small businesses in response, Martin said. He said police also have advised store owners not to keep a large amount of cash on hand and to make sure their surveillance systems are working properly.

Martin urged shopkeepers and business owners to remain vigilant. The burst of crimes is unusual, he said, and with a firearm involved, investigators are taking the crimes very seriously.

“We get a fair amount of (armed robberies) throughout the year, and they’re usually drug-related,” Martin said. “(But) to have so many and with the similarities so much the same in a short amount of time, it’s definitely an uptick.

“And the potential for violence is so high. An armed confrontation between officers could occur, or an armed confrontation with a citizen trying to stop a robbery (could occur).”

Police also have called on the FBI and the Maine State Police to help share intelligence about the robberies and alert surrounding police departments about the nature of the crimes in case a business in their town is victimized.

The latest robbery, at the China Taste restaurant on Washington Avenue in Portland, was reported at about 8:40 p.m. Sunday. A gunman entered the restaurant and demanded cash while he brandished a semi-automatic handgun. Police described the gun as having a silver top slide and a black lower frame.

The suspect fled the restaurant when employees from the kitchen came out to investigate what was happening, and no cash changed hands, police said.

After the attempted robbery Sunday night, a police dog tracked the suspect a short distance to Maine Avenue, where the suspect likely fled in a vehicle, Martin said.

“We’re confident that Maine Avenue was the escape route,” he said. “(We’re asking) anyone who has surveillance cameras, video setups, to review them. Most likely the person parked the car, watched the place for a while until they felt comfortable and then went in. It would most likely be a vehicle not familiar to the neighborhood.”

The suspect in the Portland robbery is described as a white man about 5 feet, 5 inches tall. He was wearing an oversized hooded sweatshirt with a dark green and light green camouflage pattern and had the hood pulled over his head. He also was wearing a dark-colored zip-up shirt under his outer clothing and had it pulled up so that it partially hid his face, Martin said.

The employee working in the Subway when it was robbed Monday night told Consiglio, the store manager, that the suspect was about 5 feet, 10 inches tall. Police said he displayed a black gun and was wearing a dark blue hooded sweatshirt and dark pants.

Martin said detectives from the departments are working hand-in-hand to share information and dig up new leads. He also encouraged the public to call officers if they believe they have any information that could help.

Martin also urged business owners to “be the best witness you can” in the event of a robbery.

“Listen to the robber’s commands. Listen for speech impediments, dialects, phrases they use. (Watch for) clothing details. Walks with a limp, or is right- or left-handed. Things like that. Look at the height on the door markers. Direction of travel is incredibly important. If a person leaves in an area, tell that to a dispatcher. If you do have surveillance video cameras, put ’em out. If you’re near a convenience store, always review them after something happens.”

The description of the suspect in the robbery at China Taste is similar to descriptions provided to police by employees of other businesses robbed in the past week, including a coffee shop in Westbrook.

On Saturday, a man on foot entered The Daily Grind drive-through on Main Street in Westbrook shortly before 8 a.m., brandished a handgun and threatened a 16-year-old employee. The suspect fled on foot, Westbrook police said.

Sue Salisbury, who bought The Daily Grind with her husband more than a year ago, said her teenage daughter was the employee who came face-to-face with the robbery suspect Saturday morning. After hearing a knock on the back door of the drive-through section of the business, the teen opened the door thinking it was her stepfather, Joe Salisbury.

“(The robber) told her he wanted her to open up the cash register and assured her he wasn’t going to hurt her,” Sue Salisbury said. Sue Salisbury said the suspect had his hood up and his face was covered by a mask. After he left, Sue Salisbury said her daughter called for her stepfather, who was working in another part of the business. He alerted police. The Salisburys said they turned over footage from three surveillance cameras to investigators.

The Daily Grind had to close for the day Saturday while police investigated. On Sunday, regular customers and friends streamed into the business to buy coffee and food, leaving behind extra change to help make up for the financial loss the day before. Many hugged the Salisburys and offered their support.

“As a new business, it’s hard to have something like this happen and have to close for the day,” Sue Salisbury said. “Our customers realized the impact – the mental aspect of being robbed, but also the economic impact of that.”

Sue Salisbury said her daughter – whom she declined to name out of concern for her safety – was scared by the robbery, but is “really strong.” She did not want to be interviewed. She was scheduled to return to work Monday afternoon.

The first robbery was last Tuesday night at the Riverton Gas Station on Forest Avenue in Portland. The robber had a silver handgun and was described as a man about 30 years old, 5-foot-5 with a thin build and wearing a heavy dark jacket, dark gloves and a ski mask.

On Wednesday, Falmouth police searched for a man who flashed a gun at the Lil’ Mart store on Route 1 around 8 p.m., then fled with some cash. He was described as white, wearing a gray hooded sweatshirt, face mask and black gloves. A manager at the store declined to comment Monday.

The next day, a white man robbed the Good Things Variety on Saco Street in Westbrook around 1 p.m. Police unsuccessfully tracked the robber with a dog. He was described as 5-foot-8, with a skinny to medium build and wearing a blue sweatshirt or fleece vest with yellow lettering, a face mask and sunglasses.

The manager of the variety store said Monday that the robber entered the store and waved a gun at him and other employees.

“We didn’t have time to get scared. He said to back up and he wanted us to open the (cash register) drawer. We opened it and backed up a bit,” said the manager, who would only identify himself by his first name, Bob, because he feared retaliation.

The manager said one employee, who was not working at the time, quit because of the robbery. It was the first time the store had been targeted by a robber, he said.

The next day in Cumberland, someone robbed the Irving gas station at 174 Main St. at 8:44 p.m., police said.

Portland police are asking people who live near the China Taste restaurant to check their home surveillance systems to see if any vehicle or pedestrian traffic was recorded around the time of the Sunday evening robbery. Anyone with information can call Portland police at 874-8575.

Matt Byrne can be contacted at 791-6303 or at:

mbyrne@pressherald.com

Twitter: MattByrnePPH

Gillian Graham can be contacted at 791-6315 or at:

ggraham@pressherald.com

Twitter: grahamgillian