SOUTH PORTLAND — Police are looking for two teenagers suspected of trying to rob a Cottage Road convenience store at knife-point late Tuesday.

Police Lt. Todd Bernard said two school-aged boys, each estimated to be 15-17 years old and 5 feet 6 inches to 5 feet 8 inches tall, entered the Big Apple at 11:47 p.m. wearing ski masks and dark jackets. One of the boys displayed a knife and demanded money from the cashier. The other boy stood by and watched, Bernard said.

The clerk did not comply with the demands of the would-be robbers, who were then confronted by a customer who was in the store at the time. “They were a little frustrated and grabbed a pack of Mentos and fled the store,” Bernard said.

Police on Thursday said the suspects were last seen running towards Harriet Street and were tracked by a police dog to the area of Broadway and Harriet. One suspect was described as wearing a black winter jacket with a distinctive white stripe wrapping around the back and down the sleeves; he also had a backpack. The other was wearing a sweatshirt and hat.

Anyone who has information about the crime is asked to contact the South Portland Police Department at 799-5511.