Cambridge police arrested seven Arlington males in connection with a Friday night shooting in Harvard Square, officials said yesterday. Police are still searching for other suspects.

At least one of the suspects will be charged with assault with intent to murder at the arraignment this morning at Cambridge 3rd District Court, according to Detective Frank Pasquarello, spokesperson for the Cambridge Police.

Four of the suspects will be charged with assault by means of a dangerous weapon and the others with disorderly conduct, Pasquasrello said.

Pasquarello, who said some of the suspects were juveniles, refused to release any of the names until this morning. He did say that the person suspected of firing the shots was not a juvenile.

The shooting broke out at 8 p.m. after "two groups of kids got into a fight," Pasquarello said.

Pasquarello said it was "not gang related," and he said police are investigating the motive.

One of the suspects allegedly pulled a .38 caliber gun and fired five to seven shots at a member of the other group. No injuries were reported.

"We're lucky no one was killed," Pasquarello said. "There is definitely a possibility that someone could have been killed."

Pedestrians in the Square hit the ground after the shooting began, and police were on the scene within seconds. According to eyewitnesses, police arrested two suspects after they ran through Urban Outfitters.

Harvard Detective Hubert Estesarrested a third near the Apley Court complex on Holyoke Street, eyewitnesses said.

Pasquarello attributed the quick response to the fact that Harvard Square is a "hot spot" on Friday night and a high number of undercover police patrol the area.

Pasquarello denied the rumor that this was a failed drug bust by the Cambridge Police.

"It was good old-fashioned police work," he said. "They were in the right place, where they should be. They didn't expect any trouble."

One bullet shattered a window at BayBank, one hit a wall near the window and a third bullet hit a mailbox in front of the bank, police said.

Police recovered a box of .38 caliber cartridges after the shooting, Pasquarello said.

Bystanders Shaken

Lucia A. Petrulli, a Somerville resident, was sitting in her car outside of Out of Town News waiting to pick up a friend.

"I was frightened," Petrulli said yesterday. "I heard four or five shots and I though, 'Oh, my God.' Harvard Square is the last frontier."

Petrulli said she would be "more wary" when she goes to the Square in the future.

Pasquarello said this was one of the most dangerous incidents he remembers happening in Harvard Square in the last five years.

"How would you know, in the middle of Harvard Square, someone would pull out a gun and start shooting?" he asked.

But Pasquarello said people should not change their daily routines because of the shooting. "Just do what you naturally do," he said. "This could happen at any part of the city.