WASHINGTON-Mayday organizers are making last-minute adjustments here today as antiwar demonstrators pour into the city for Monday's civil disobedience aimed at closing off downtown Washington.

About 1500 demonstrators organized by the People's Coalition for Peace and Justice (PCPJ) surrounded the Justice Department yesterday, effectively blocking the building's seven entrances for over two hours. Police arrested 335 protesters on charges of disorderly conduct and unlawful assembly, bringing the total number of arrests in the past week to over 1000.

Hosea Williams, national program director of the Southern Christian Leadership Conference (SCLC), was among those arrested yesterday. Williams arrived at the Justice Department at about noon with over 600 demonstrators from the Algonquin Peace City situated two miles away at West Potomac Park.

Up until that point, about 150 PCPJ lobbyists had used sit-in and picketing tactics to force to close two of the seven entrances. The first door blocked was the entrance to the FBI.

When Williams's group arrived, the crowd was able to seal off all of the entrances simultaneously-preventing Justice Department employees from returning to work from their lunch breaks.

At a main door on Pennsylvania Avenue, police helped employees struggle over and through a group of about 300 demonstrators who formed a "human carpet" five people deep.

Police began arresting demonstrators at 1:15 p.m., clearing the entrances to the building one at a time.

The Reverend Ralph D. Abernathy, chairmanof the SCLC, also addressed the crowd but was not arrested. Hundreds of employees from the Justice Department and the adjacent Internal Revenue Service building watched quietly from across 10th Street as police cleared the demonstrators.

The main gate to the Justice Department on 10th Street remained obstructed by a crowd of about 500 until almost 3 p.m., when police made the final series of arrests and took over 200 people into custody.

Demonstrators were warned ahead of time that they should clear the areas in front of the doors or face arrest. When police moved in, the demonstrators did not resist although a few went limp.

Police again refused to allow demonstrators to post collateral yesterday, and arraignments began at about 4:30 p.m.

The rules committee of the Washington Superior Court Thursday refused a request by police chief Jerry V. Wilson to raise collateral from the customary $10 to $50. Wilson reportedly wanted to raise the collateral in order to further strain the bankrupt Mayday bail fund.

Mayday organizers yesterday reduced from 22 to nine the number of targets where protesters will attempt to block traffic Monday in the hope that concentrations of regional groups will be more effective than single groups at scattered targets.

Deputy Attorney General Richard Kleindienst said yesterday that 7300 police and national guardsmen will be on hand Monday to control the Mayday demonstrations. He dismissed the demonstrators' vow to shut down the government as "just a lot of hot air."

"At worst this is going to be a minor irritant," police chief Wilson told Republican legislators at an early morning meeting at the Old Senate Office Building. "We are making arrangements to get everybody to work and we do not expect traffic disruptions to be a major problem."

Mayday organizers lost a battle to move today's rock concert to the Washington Monument grounds in order to reduce the possibility that concert, goers will disrupt planning sessions for Monday's action.

Kleindienst denied their request for use of the grounds at midday yesterday, saying he did not want to prevent tourists from visiting the monument tomorrow.

Kleindienst's ban may also interfere with a Mayday women's march scheduled to originate at the Monument grounds tomorrow. Today's concert will begin at noon and last through the night. Another concert will be held tomorrow following a mass rally sponsored by PCPJ and the Mayday Tribe.