South Portland police have charged a Westbrook man and two teenagers in connection with a Saturday armed robbery in which two teenage girls were robbed of their pocketbooks at gunpoint in the Brickhill area of the city.

The girls knew one suspect in the incident, which triggered an intense investigation in Westbrook and Auburn as well as South Portland.

Police served four search warrants and arrested the two juveniles at 14 Newbury St. in Auburn on charges of robbery. Police say the youths have connections to Greater Portland but do not have a fixed address.

Police also charged Devon Grant, 18, of Westbrook with trafficking in dangerous knives.

On Monday, police searched 53 Haskell St. in Westbrook and subsequently charged 18-year-old Samnang Im, also known as “Junior Sok,” with two counts of robbery stemming from Saturday’s incident and a similar one in Westbrook on Thursday.

Im is being held without bail because of a charge of violating bail conditions from a previous arrest, police said. He is scheduled to appear in court Wednesday.