LOS ANGELES -- For the past few years, many residents of Ramona Gardens took pride in a remarkable turnaround.

Once controlled by a Latino gang, the Boyle Heights housing project had seen crime drop dramatically. Moreover, black families were beginning to move back into the rows of garden apartments -- more than 20 years after the firebombing of two black families prompted most blacks to flee.

Then on Monday night, someone threw flaming Molotov cocktails at four apartments in Ramona Gardens. It had all the hallmarks of the racial attack from the area's darker years.

Three of the four apartments targeted just after midnight were occupied by black families. The other housed a Latino family. No one was injured in the attack. Police have no suspects and have been careful to say the motive remains unclear.

But several law enforcement sources familiar with the investigation said officials believe the attack was racially motivated. The apartment the Latino family stayed in was tucked amid the others. The sources spoke on condition of anonymity because they were not authorized to discuss the incident.

The FBI is working with the LAPD to determine whether any federal civil rights statutes were violated in the attack, bureau spokeswoman Laura Eimiller said Friday.

Either way, the damage has already been done. Some black families immediately put in for emergency transfers to other housing projects, according to police.

A few didn't wait for transfers and simply left. Others are debating what to do.

CJ Johnson, 32, said his family probably will leave soon.

Johnson, a black resident who works with special needs children and is married to a Latina, said the attack "came out of the blue."

"It's been peace and love with my family," he said. "I haven't had any issues. I'm a family man and they respect that."

One black woman, who asked not to be identified out of concern for her safety, said she has asked for an emergency transfer.

She moved to Ramona Gardens about a year ago and said the atmosphere has been calm until this week. Now, she said, she doesn't want to take any chances.

"I have a 17-year-old son," she said.

There are 23 black families living in Ramona Gardens, which is predominantly Latino. That number has increased since last year, when at one point 16 black families lived in the housing project. The complex has about 1,791 residents.

The violence was a blow particularly to a group of residents -- including former gang members -- who had been working to ease racial tensions and make blacks feel welcome. Even after this week's firebombing, it's not unusual for black and Latino residents, especially children, to mingle and talk.

In 1992, the homes of two black families were firebombed, sending adults and children fleeing into the street. Soon other black families left, leaving Ramona Gardens with virtually no blacks for almost 20 years.

That began to change in recent years as black families returned. The LAPD, residents, gang intervention workers and others collaborated to keep them safe.