By JOSEPH PANOSSIAN, Associated Press Writer BEIRUT, Lebanon – Lebanon’s pro-Syrian president said Saturday that he will not attend an Arab summit because of political turmoil in his country as investigators searched for clues to a car bomb that rocked a largely Christian neighborhood in Beirut, injuring nine people. President Emile Lahoud did not elaborate on his decision not to participate in Monday’s summit in Algeria, but it came as Syria withdraws troops from Lebanon after facing heavy pressure from the United States and fellow Arab countries to end a three decade presence. The attack devastated an eight-story apartment building in the largely Christian New Jdeideh neighborhood shortly after midnight on Saturday and sent panicked residents in their pajamas into the street.

Lahoud, a close Syrian ally, made no mention of the attack, saying only in a statement that Lebanon was experiencing “exceptional circumstances” that required “immediate and direct dialogue” between opposition and pro-government groups.

He also offered to host immediate talks between Lebanon’s various political factions amid negotiations over the formation of a new government.

Opposition legislator Fares Soeid dismissed the invite, saying: “It’s too late. This subject is closed.”

The violence raised concerns among some Lebanese that pro-Damascus elements might resort to violence to show, in their view, the need for a continued presence by Syrian forces. Hundreds of thousands of Lebanese have demonstrated for and against Syria since the Feb. 14 slaying of former Prime Minister Rafik Hariri. The anti-Syrian protests have featured large numbers of Maronite Christians.

Police closed all entrances leading to the blast site and blocked onlookers from nearing the devastated building. After sunrise, residents began clearing debris and inspecting their damaged shops and homes.

The Lebanese military also announced stricter measures against any security violators. “The army will not allow that freedom of expression be abused in order to harm security and stability,” it said in a statement.

Security officials said on condition of anonymity the blast was caused by a time-bomb underneath a car belonging to a Lebanese-Armenian resident of the damaged building. The whereabouts of the car owner were not known.

Earlier, witnesses said the car attempted to stop in front of a bingo hall, but security guards asked its driver to move along. The driver then parked the car a short way down the road. Minutes later it exploded.

Opposition leader Walid Jumblatt warned there could be more car bombs and assassination attempts but urged calm.

“Car bomb messages do not threaten our national unity,” Jumblatt said in a speech to supporters at his mountain palace of Mukhtara, southeast of Beirut.

The leader of the militant group Hezbollah, which is backed by Syria and Iran (news – web sites), warned the opposition against closing the door to dialogue. That “could take the country to an unsafe place and create an atmosphere that the enemies of Lebanon might use, as happened last night,” Hassan Nasrallah said Saturday.

Political demands from factions for and against Syria have bogged down efforts to form a new government, raising concerns that the deadlock could threaten upcoming elections and even Syria’s final withdrawal.

Pro-Damascus premier-designate Omar Karami, whose previous government was forced to resign as anti-Syrian sentiment increased, has insisted on a “national unity” government. But the opposition is refusing to join unless its demands are met. The opposition wants a neutral Cabinet to arrange for elections, the resignation of security chiefs and an international investigation into the blast that killed Hariri and 17 other people.

Many have linked the Lebanese and Syrian governments to the killing; both governments deny any involvement.

Some opposition members accuse Karami of stalling to destroy chances of holding an election they believe the pro-Syrian camp will lose.

Jumblatt told Future Television that parliamentary polls should be held as planned for April and May. “Let them hold the elections according to the electoral law they deem suitable, but we will not participate in the government,” he said.

Saturday’s explosion blew off the fronts of some structures, left a seven-foot-deep crater, damaged parked cars and shops and shattered windows for several blocks.

Christian opposition member Pierre Gemayel linked the attack to the Syrian troop pullout.

“This has been the message to the Lebanese people for a while — to sow fear and terror among Lebanese citizens,” he told Al-Jazeera satellite television. The message is “if there is a Syrian withdrawal from Lebanon, look what Lebanon will face.”

The intensity of the political battle over Syria’s troops has raised fears of a return to the sectarian violence of Lebanon’s 1975-90 civil war. So far, however, the political camps do not conform to religious boundaries, with Christians and Muslims on both sides of the debate.

On Thursday, Syria completed the first phase of its withdrawal in Lebanon, redeploying all its remaining soldiers and military intelligence officers to the eastern Bekaa Valley. Of the 14,000 troops that were in Lebanon last month, at least 4,000 soldiers have returned to Syria.

At the United Nations (news – web sites), Maronite Cardinal Nasrallah Sfeir said that Syria had given assurances it would withdraw its troops before the country’s elections, as U.N. and American officials want.