Mayor Marion Barry stood in the middle of Hanover Place NW yesterday, the city's most notorious and brazen cocaine market, and said the city had retaken the block from drug traders .

The mayor, accompanied by Assistant Police Chief Isaac Fulwood and other top police officals, visited the scruffy, dead-end block-long street following Tuesday's late night raid by about 80 police and FBI agents who sealed off the street, demanded identifications from about 75 people, executed seven search warrants and made seven arrests. Various gun and drug possession charges were laid against the seven suspects.

The raid -- the third in 18 months -- was dubbed "Operation Avalanch," and kicks off what the mayor called an intensive city program that will include trash cleanup, strict housing code enforcement, installation of brighter street lights and more police patrols for the 18-block area around Hanover Place.

"We are serving notice on the drug elements here that the District will not tolerate this condition, that it will stop," the mayor said. "The residents deserve to live in peace and decency."

But neighborhood residents who have witnessed the three-year-old off-again, on-again guerrilla war between police and drug pushers said they doubted the city's newest show of force would have much lasting effect.

Artist Eric Rudd, who owns a large warehouse that backs onto Hanover Place, said just before the news conference that he watched from his window and saw two of the area's regular drug dealers walk down an alley counting $100 bills.

"When they reached Hanover, they saw the police and made a U-turn and just walked back out," said Rudd, who attended the news conference. "I've seen two other operations like this and they are nice for as long as they last. What I can't understand is why it takes attention from the media to get results down here. We all have made our calls and written letters but nothing ever happened."

Rudd said he was referring to an article that appeared in The Washington Post last week detailing gunfire associated with the drug trade around Hanover Place and the emergence of that market as a possible battleground for rival East Coast drug dealers.

Etta Irene Davis, another resident, tried unsuccessfully during the 30-minute news conference to ask the mayor why the police and city sanitation workers had not responded when she and other residents called to report problems and disturbances on the street that is located just off North Capitol Street near New York Avenue.

Later she said in an interview, "I want to know why they laugh at me when I call for help. They think because I live in the ghetto, that I don't count. I'll tell you what I think about what the mayor said about taking care of us residents. I think he is a liar."

She added that a son and two newphews, whom she brought up, had died in drug-related shootings near Hanover Place.

Uniformed police once again stand guard at various entrances to Hanover Place, which is surrounded by a honeycomb of alleys. They stop would-be customers, many with Maryland and Virginia license tags, who did not know the police were back in force.