D.C. City Council Chairman David A. Clarke urged Mayor Marion Barry yesterday to limit the use of police roadblocks as they were used in the District on Saturday during a major citywide drug crackdown.

"The use of roadblocks is a serious matter, involving the involuntary albeit brief detention of innocent citizens and should be used with circumspection and only when necessary for serious purposes," Clarke said in his four-page letter to the mayor.

Clarke also said in the letter that roadblocks are "more characteristic of totalitarian societies."

Clarke's letter was prompted by the arrest of more than 400 persons in an antidrug operation over seven hours Saturday called "C-Note Sevenfold."

Police set up roadblocks as diversions in all but one of the city's seven police districts, and demanded that drivers produce licenses and vehicle registration.

Meanwhile, officers throughout the city covertly observed illegal drug sales in the major drug marketplaces. Officers then arrested alleged drug buyers and some sellers as they left the area.

Police also said they made several arrests at the roadblocks for drunken driving and driving without a license and gave out numerous traffic citations.

Clarke said he does not intend to introduce a City Council measure to restrict police roadblocks or to take any other action.

"Some public official ought to have the guts to stand up and speak out" against the roadblocks, Clarke said at a news conference yesterday after a meeting with Barry in which he explained his objection to the roadblocks.

"Mr. Clarke is entitled to his own opinion," Barry said yesterday in a statement read by a spokesman. "What police did is legal. If it takes roadblocks and other legal means to get at the drug dealers, pushers and users, we're going to do it. The temporary inconvenience to citizens is worth it. The public is ready for the city to move on ridding the city of drugs."

Clarke also said that he brought up his objections to Assistant Police Chief Marty Tapscott, acting yesterday in Chief Maurice Turner's absence, and that Tapscott defended the operation.

Tapscott and other police officials declined to comment on Clarke's statement yesterday.

On Monday, police officials said it was likely that police would plan other drug sweeps, but probably would not use roadblocks as diversions because they believe many drug dealers are wise to the tactic.

Police in the 1st, 3rd and 7th districts have used roadblocks as diversions in past drug crackdowns. In addition, D.C. and Montgomery County police and police in other jurisdictions have used roadblocks to catch drunken drivers.

In his letter, Clarke said that he does not object to drug sweeps or to the use in general of police roadblocks. He said he objects, however, to using roadblocks as a diversion for some other police operation.

Roadblocks "should be limited to those situations where it is thought that something bad or something urgent will be coming through," he wrote.

Clarke quoted Tapscott as saying that "very few" of the 302 people arrested on drug charges in the operation Saturday were arrested at the roadblocks.

The American Civil Liberties Union has objected to last week's use of roadblocks, charging that they infringe on the Fourth Amendment's guarantee of freedom from warrantless searches and seizures. Arthur Spitzer, legal director of the Washington area ACLU, said his group is considering filing suit against the city to challenge the practice.

In setting up the roadblocks, police relied on a 1977 Supreme Court ruling that said police cannot legally detain some drivers while letting others go arbitrarily, but can set up roadblocks to detain all drivers in a given area.

"I don't believe that since the Supreme Court said they're legal, they should be used in every instance," Clarke said. He called roadblocks a "quantum leap" in government's intrusion on people's lives.