About 8000 antiwar demonstrators last night sparred for several hours with about 300 riot-equipped Boston police outside the Commonwealth Armory, where Pat Nixon was speaking at a Republican fund-raising dinner.

The demonstrators demanded that the Nixon Administration sign the nine-point peace program made public last week by the North Vietnamese.

Chanting "Sign it Now," the demonstrators initially surged against police but were immediately repulsed by a police counter-advance.

The police, bolstered by six mounted officers, kept the protesters massed on one side of Commonwealth Avenue about 100 yards from the Armory, allowing the 6000 Republican dinner guests to stroll into the building unimpeded.

The demonstrators remained on one side of Commonwealth Avenue in a stalemate with the police for about three hours. During that time, the street was closed to both automobile and MTA traffic.

Five persons were arrested in the initial police advance. During this 15 minute melee, two sections of a fence running down the middle of the MTA median strip were demolished. Following the initial skirmish, the protesters crowded on their side of the street, and listened to speeches and jeered at Republicans who entered the armory.

They tossed several firecrackers admonitions from demonstration leaders to keep the action peaceful. One police photographer was hit by a brick and taken to a hospital.

The police faced the protesters along a 300-yard front down the middle of Commonwealth Ave. About 150 members of the elite Tactical Police Division were in the vanguard, backed by two other police lines.

About 50 Massachusetts State Police guarded the entrances to the Armory, while numerous plainclothesmen circulated through the crowd.

After the three-hour statement, an automobile belonging to the Boston Record American-Herald Traveler was set on fire at one end of the skirmish line. As Boston firemen extinguished the blaze, police herded the rest of the crowd--which had now dwindled to about 2000--west down Commonwealth Ave.

The demonstrators had arrived at the Armory at 7 p.m. after marching from several locations. The bulk of the marchers left a Copley Square rally at 6:20 p.m. and surged up Commonwealth Ave. behind a small police escort.

Waving a forest of NLF flags and picket signs, the matchers chanted "Dump Nixon, Dump Thieu, End the War in '72," Picket signs read "Trick or Treaty" and "Nixon Eats Shit--$1000 a Plate."

At the Copley Square rally, about 3000 people gathered to hear speeches by Boston University professor Howard Zinn and antiwar activist David Dellinger.

Zinn told the gathering that "the war can't wait for the Nixon Administration to sign this agreement" and urged that the U.S. "sign it now."

"We are here because we think that this Administration is an abomination," Zinn said. "If the U.S. wanted this war to end tomorrow, the war would end tomorrow."

Dellinger, the last speaker at the rally, called Nixon's willingness to consider the North Vietnamese peace plan an "election maneuver," but added that Nixon has been "trapped by the longing of the American people to end the war."

"They are reaching for signs--in Vietnam, in world opinion, and here in the U.S.," Dellinger said. "That's why we're here tonight."

Yesterday's action was staged by the Indochina Peach campaign, the Penny-a-Plate Committee, the Campus Coalition and other groups