Blast Kills Dozens in Pakistan

Bush condemned the attack, calling it "part of a continuing assault on the people of Pakistan."

"We will assist Pakistan in confronting this threat and bringing the perpetrators to justice," he said. "We will fully support the democratically elected government of Pakistan and the Pakistani people as they face enormous challenges economically as well as from terrorism."

Witnesses and residents of the modern, heavily policed capital said they heard the explosion several miles away. The bomber detonated his explosives-laden truck during iftar, the evening fast-breaking ritual during the Muslim holy month of Ramadan.

The building continued burning into the night, and officials said the hotel might collapse.

The Marriott, which is near the Parliament, the presidential offices, the Supreme Court and other major institutions, is a center of the capital's social and political scene and a favorite of foreign business visitors, journalists and diplomats.

Security at the hotel is always heavy, with all vehicles searched outside the entrance. The hotel has been attacked twice before. In January 2007, a suicide bomber triggered a blast nearby, killing a security guard and wounding seven.

Islamabad has been hit by a wave of attacks in recent months. In March, a woman was killed in a bombing at an Italian restaurant popular with foreigners. In June, a suicide bomber attacked the Danish Embassy, killing six people. In July, 18 people were killed in a suicide bombing on the anniversary of a government-led raid on a radical mosque.

Television footage Saturday night showed the Marriott's spacious lobby, known for its 24-hour buffet, society weddings and constant political meetings, as a charred ruin. Dozens of vehicles in the parking lot had been rendered twisted hulks of metal.

Constable reported from Kabul.