SAN SALVADOR, El Salvador (AP) _ Many residents of the affluent Escalon neighborhood, including about 20 U.S. citizens, took advantage of a brief guerrilla truce and fled the battle zone today.

The leftist rebels launched a second assault on the capital Wednesday and turned their weapons on wealthy districts, where they seized homes, forcing scores of Americans to take refuge in the U.S. Embassy.

Rebels were dug into the neighborhoods late Wednesday, vowing to paralyze the heart of the country's wealth and power.

But the rebels had declared a six-hour truce beginning at 6 a.m. (7 a.m. EST) for evacuation of those who wished to leave, and Escalon was mostly quiet this morning, with only scattered gunfire.

It appeared most of the rebels retreated shortly before dawn up the lower slopes of the San Salvador Volcano, which looms over the district. However, some evacuating residents said rebel snipers remained in the their homes.

The bodies of at least nine soldiers lay on the streets. Reporters saw only one dead guerrilla, a woman still clutching her U.S.-made M-16. The total number of casualties was not known.

Several Americans said they planned to leave the country this evening on the first of several charter flights arranged by the U.S. Embassy. Diplomatic sources said about 250 U.S. citizens would fly out this evening.

''I'm not coming back,'' said Kate Lewis, who carried her 8-month-old baby Cassandra from their home down Mirador Street to where an embassy official was waiting for them. Her husband, William, was barefoot.

Both are teachers at the American School. About 30 guerrillas took over their home before dawn Wednesday. They were accompanied by two other teachers, Sam and Sheri McKibben.

Small groups of residents carrying belongings gathered on almost every street corner in the 20-square-block area.

The embassy official awaiting the Lewises, said 12 U.S. households had family members who spent Wednesday night in Escalon in rebel-controlled areas.

The official, who declined to give his name, said all the Americans left the neighborhood this morning. Other U.S. citizens managed to leave Wednesday.

Some Salvadoran residents said they were staying to protect their homes.

The winding, hilly streets were blocked at intervals by barricades of cars, most of them with their tires shot out. A burned-out light tank destroyed by a rebel rocket sat on the street up from the Lewis' house.

Many Americans had earlier taken refuge in the embassy or the headquarters of the U.S. Agency for International Development headquarters in areas well away from the fighting.

About 100 Americans, almost all women and children, spent the night at the U.S. Embassy and were to leave today in a chartered jet, embassy spokesman Barry Jacobs said.

Jacobs said the Salvadoran national airline TACA planned extra flights for the next few days to carry others. He refused to call it an evacuation, saying that embassy dependents were given extra leave for Christmas vacation. ''No one is being made to go,'' he added.

There are between 8,000 and 10,000 U.S. citizens in El Salvador at any one time about 400 to 500 of them are employees of the embassy and the Agency for International Development and their dependents, Jacobs said.

Guerrillas seized a U.S. Embassy employee's home Wednesday, but the family was allowed to leave the area unhurt, the State Department said in Washington.

The home of an embassy employee also was reported burned during the fighting, but it was not clear if it was the same house or if the fire was set deliberately. Embassy officials refused to give any other details.

The embassy, miles away near downtown San Salvador, told its employees not to try to get to work.

Japan's diplomatic liaison office, about four blocks from U.S. Ambassador William Walker's residence, was taken by the rebels, but the few people inside were allowed to leave escorted by rescue workers, a Salvadoran Foreign Ministry source said. In Tokyo, a Foreign Ministry official denied the office had been taken but said staffers reported fighting in the neighborhood.

A Western diplomat said the guerrillas had also seized the residence of a mid-level French diplomat, allowing those inside to be evacuated.

Jeff Brown, another U.S. Embassy spokesman, said perhaps 100 to 200 rebels had taken positions Wednesday in Escalon and Benito, heavily armed and moving in small groups. The rebels issued a statement in Washington on Wednesday saying their fighters were under orders not to attack U.S. citizens.

Guerrillas seized the homes of three wealthy Salvadorans, but freed the people inside ''to demonstrate'' they were a ''responsible force'' fighting for ''democracy,'' the rebel broadcast said.

The broadcast by the leftist Farabundo Marti National Liberation Front rebels called Wednesday's attack part of a ''constant strategic siege on the capital city, the nerve center of the nation.''

Dagoberto Gutierrez, a rebel commander, said Wednesday's attack was the second wave of an offensive first launched on the capital Nov. 11, during which an estimated 1,000 people were killed.

The first phase turned slums and poor neighborhoods into battlefields for 12 days, sending tens of thousands fleeing.