LEWISTON — A masked man with a gun robbed a Lisbon Street gas station Thursday night, prompting a search involving several police officers and a tracking dog.

The robbery was reported shortly after 8:30 p.m. at USA Gas at 1892 Lisbon St. The suspect aimed a gun at the store owner and demanded money before fleeing on foot.

The man who owns the store said it was the second time this week that his business was robbed at gunpoint.

The suspect was said to be wearing a hunting mask during the stick-up. Witnesses reported that he was last seen running on outer Lisbon Street.

Lewiston police swarmed the area, checking side streets and parking lots in search of the suspect.

Lisbon police were notified of the heist and sent a tracking dog to the area. An hour after the robbery was reported, the armed suspect remained at large.

According to the owner of USA Gas, who identified himself as Elias, the store was also robbed Monday night. In that heist, he said, the suspect held a gun to Elias’ head and made off with all of the money in the register.

On Thursday night, the suspect aimed the gun at Elias and emptied the register of more than $200.

USA Gas typically stays open until 9:30 p.m.

“I guess we’re going to have to change it to 8 o’clock now,” Elias said.

According to a police bulletin issued minutes after the Thursday night robbery was reported, the suspect is about 5 feet, 10 inches tall and wearing jeans and a black jacket.

Elias was not hurt in the robbery. Police were interviewing him at the store later Thursday night.