Police are investigating an attack in Portland’s West End Thursday night that may have involved a Taser.

A man reported that he was walking at Pine and West streets when he was attacked from behind. The man said he heard what sounded like an electric stun gun and felt a sharp pain in the back of his neck, police said.

The man turned and was punched in the face. As he ran away east on Pine Street, he heard what sounded like a gun shot, police said.

Police are looking for three white men, 5’10” to 6’2″ in their early 20s all wearing white T-shirts. A fourth suspect was described as a black man in his early 20s, 5’9″ and 165 pounds wearing jeans and a blue shirt, police said.

Police asked that anyone with information call 874-8596.