A 13-year-old Chelsea boy took a stray bullet to the shoulder last night while he was inside his family’s home, police said.

Cops said a fight between two groups of youths in the street led to the shooting. After shots were fired, they were called to a third-floor apartment on Bellingham Street.

“Inside that apartment officers found a 13-year-old male that was struck by a stray bullet fired from the street,” police said. “The victim who was with family received a non-life-threatening gunshot wound to his shoulder.”

The boy was taken to Massachusetts General Hospital.

Friends of the victim were stunned.

“He’s a good kid. Gets good grades. Plays video games and stays out of trouble,” said a man at the scene who knows him.

Chelsea police Chief Brian Kyes called the boy an “innocent victim” and said he was not the intended target of the gunfire.

He said there have been no arrests, and no weapons were recovered by det-ectives at the scene. Two suspects fled the scene in a dark-colored Ford Explorer,he said.

“The investigation is on­-going,” he said.

A woman at the scene said she was relieved the boy wasn’t seriously injured.

“Thank God he’s going to be OK,” she said. “He’s a really good kid.”

Chelsea police are asking for anyone with information to call investigators at 617-466-4800 or provide information anonymously at chelseapolice.com.