BEIRUT - A bombing in a Christian suburb of east Beirut overshadowed Easter celebrations Sunday and raised fresh fears of a slide back into Lebanon's violent past.

Lebanese security forces picked through rubble and twisted metal left by Saturday's blast, the third in eight days in the Christian heartland, where resentment against Syria runs high.

Patriarch Nasrallah Butrous Sfeir, spiritual leader of Lebanon's Maronite Christians and a long-time critic of Syria's grip on Lebanon, told worshippers at Easter mass the Lebanese must now choose between freedom and violence.

"The holiday this year does not give the faithful worldly cheer," he said. "The incidents ... put (people) at a crossroads: either independence, sovereignty and freedom - - and that is what most Lebanese want - - or turmoil and difficulties."

Lebanon's pro-Syrian President Emile Lahoud urged unity.

"We must be united. This is what will save the nation," he told LBC Television, after meeting Sfeir.

The blast wounded eight people, security sources said, most of them migrant workers from South Asia.

They said 25 kg (55 pounds) of high explosives had been planted between a Buick car and a car repair shop and exploded in the Sad al-Boushrieh industrial zone.

The United States condemned the blasts and urged Lebanon to push ahead with elections due in May but threatened with delay if a crisis over the formation of a new government continues.

"The people of Lebanon are confident in their ability to proceed in manner that tells those responsible they will not be frightened," U.S. Deputy Assistant Secretary of State David Satterfield said after meeting opposition leader Walid Jumblatt.

International Probe

Anti-Syrian opposition figures blamed the Lebanese security agencies backed by Damascus for the blast, which revived memories of Lebanon's 1975-1990 civil war. They said the attacks would not deter their campaign against Syria.

Saturday, Lebanon's opposition, which blames Syria and its allies for the killing of former Prime Minister Rafik al-Hariri on Feb. 14, urged the country's security chiefs to resign to make way for an international probe into his death.

A U.N. fact-finding report said Lebanon's own inquiry was seriously flawed and called for an international investigation.

Lebanon's pro-Syrian authorities have criticized the report but accepted an international probe.

"These criminal acts will not make the Lebanese reverse their march to sovereignty, independence and freedom," said leading opposition lawmaker Nasib Lahoud.

By Sunday morning, wisps of black smoke were still escaping from windows and water was trickling down walls. Firefighters had worked all night to extinguish blazes in four buildings.

The killing of Hariri, a Sunni Muslim, has cast Lebanon into its biggest political crisis since the end of the civil war.

The opposition seized on mass street protests to force the pro-Syrian government to resign last month and Damascus to bow to international pressure to withdraw its forces after 30 years.

Locals blamed Syria for the blast, saying it wanted to show Lebanon was slipping into chaos as they pull their troops out.

"The enemies of Lebanon did this, those who do not want the independence of Lebanon," said Ohaness Melketessian, checking on his gutted carpentry shop. "We will see more before it eases."

Tuesday, a blast killed three in a Christian town north of Beirut, days after another injured 11 in Christian east Beirut.

Syria has pledged to withdraw and has already completed the first phase of a two-phase plan, pulling back to eastern Lebanon and withdrawing over a third of its 14,000 troops altogether.

Syrian troops left six positions in the eastern Bekaa Valley overnight, witnesses said.