A huge car bomb exploded yesterday and sent a hail of glass and twisted metal through a crowded street in the Palestinian quarter of Beirut, killing at least 35 people and wounding 250, hospital sources said.

The blast devastated the headquarters of a Lebanese leftist group, the Organization for Communist Action in Lebanon, and badly damaged several nearby buildings, eyewitnesses said. Dozens of cars were wrecked. The front walls of a seven-story building housing the investigation department of the Palestine Liberation Organization's secret service chief were blown out by the force of the explosion.

The bomb started a fire that took more than three hours to put out. Ambulances taking victims to hospitals screamed through the streets of Beirut all day. The attack was in the heart of the area used by the PLO and close to the Fakehani district of the capital, bombed by Israeli aircraft last July. The PLO said about 60 persons were killed in the blast.

The Front for the Liberation of Lebanon From Foreigners claimed responsibility for the blast. The same group has claimed responsibility for a string of bombings that have killed a total of 85 people and wounded more than 450 in Lebanon since Sept. 17.