Beirut, Lebanon ? Former Prime Minister Rafiq Hariri was killed Monday when a powerful car bomb exploded on Beirut’s fashionable waterfront, evoking the political violence that plagued Lebanon during its long civil war.

In the aftermath of the blast, which killed 13 people besides Hariri and filled hospitals with scores of wounded, including the economy minister, opposition leaders and angry demonstrators gathered in front of Hariri’s downtown mansion, blaming Syria for the most serious political assassination in Lebanon since sectarian fighting ended nearly 16 years ago. Hariri had emerged in recent months as a chief opponent of Syrian troops’ presence in the country.

The bomb exploded just before lunchtime as the former prime minister’s motorcade reached a busy curve along this seaside capital’s elegant Corniche. It left a clutter of smoldering sport-utility vehicles and sedans in a crater six feet deep, with flames flickering for hours. The explosion sheared off the facades of some of Beirut’s most luxurious hotels, shattering glass within a quarter-mile radius.

A Palestinian militant asserted responsibility for the bombing in a video aired on al-Jazeera, the Arab television network. The man said he represented an unheard-of organization and that he had carried out the bombing because of Hariri’s financial dealings with the ruling family of Saudi Arabia.

Hariri’s political supporters said they believed Syria was involved in the attack.

Lebanon’s opposition leaders blamed Syria and its allies in the Lebanese security forces for Hariri’s death and called for an immediate withdrawal of Syrian soldiers from the country.

The Syrian government, which President Bush accused of harboring terrorists in his State of the Union address, vehemently denied the charges.

Lebanese government officials linked Hariri’s killing to mounting international pressure on Syria to withdraw its troops from Lebanon.

Vehicles burn following a massive bomb attack that tore through the motorcade of former Prime Minister Rafik Hariri in Beirut, Lebanon Monday. Hariri, who resigned last fall following a sharp dispute with Syria, died in the blast along with at least nine other people. About 100 people were also wounded in the assassination, which raised immediate fears that Lebanon, largely peaceful since the 1990 end of its civil war, would be plunged into a new cycle of violence.

In Washington, the White House spokesman, Scott McClellan, said the Bush administration would consult with the region’s governments in coming days.

Hariri, 60, was a self-made billionaire who spearheaded the renovation of Beirut’s war-battered downtown.

A Sunni Muslim, Hariri resigned as prime minister in October, after holding the office for all but about five years of the country’s postwar reconstruction era.

Hariri quit the government weeks after parliament approved a term extension for the president who had been handpicked by Syria, Emile Lahoud, the former head of the Lebanese army. Hariri remained a leading member of the parliamentary opposition.

Because of the timing and size of the explosion, Hariri’s allies dismissed the claims of Ahmed Tayseer Abu Adas, the Palestinian featured on the videotape, who said he carried out the bombing on behalf of the “Group for Advocacy and Holy War in the Levant.” Lebanese security forces announced hours later that they had raided Abu Adas’s Beirut home and seized computer equipment and tapes. But he was not there.