A Justice Department official yesterday visited a low-income area of Alexandria to evaluate reports of growing tension between blacks and Hispanics and to determine if federal help is needed.

"It's hard to tell how serious the situation is," said Frank Tyler Jr., an officer of the Justice Department's community relations branch. After learning of recent incidents involving the two groups, including a bottle-throwing brawl on Sunday, Tyler said his office decided to interview police officers, city officials and residents living in Arlandria, just south of the Arlington border.

Residents' frustrations are due to poverty, overcrowding, unemployment and uncertainty over housing because of the pending renovation of 1,057 Arlandria apartments, according to police and city officials.

Mayor James P. Moran Jr. said most city officials were surprised at the federal government's intervention. "I live near that area and I don't think the problems are any worse than in any crowded community where there's high unemployment," Moran said.

But police, who are responding to an increasing number of calls in the area, said they welcomed the help, particularly if the federal agency lends Spanish-speaking interpreters and directs residents toward available resources.

Tyler said the death of a Nigerian woman whose body was found June 1 in a wooded area added to his concern about violence. Alexandria police are investigating the slaying.

Tyler also met with developers John Freeman and Conrad Cafritz, who recently signed a contract to buy 74 percent of Arlandria's run-down rental housing stock. They are expected to renovate the area for young professionals who want to live near the District. Neither developer returned calls yesterday.

Federal officials "feel there's a need for better communication between the city, the residents and the developer," said Mark Looney, division chief for the city's Landlord/Tenant Board. He said he welcomed efforts to minimize conflicts.

The Justice Department's community relations division often works with communities coping with racial and ethnic conflicts. It assisted Cubans who came to the United States during the Mariel boatlift and Korean businessmen in the District who have been the victims of a rash of violence.