Searchers combing the burnt shell of the hotel found more charred bodies the morning after the blast that reduced the Marriott to an inferno. The Czech ambassador, and an American and German national, were among those killed, while some 271 were wounded in the devastating blast, according to senior government officials.

Newspapers estimated the toll would rise to 60. Internal security in nuclear-armed Pakistan, a country vital to the war against al Qaeda and other Islamist militant groups, has deteriorated at an alarming rate over the past two years. The bombing bore the signs of an attack by al Qaeda or an affiliate, U.S. and Pakistan intelligence officials said. ?The sophistication of the blast shows it?s the work of al Qaeda,? a Pakistani intelligence officer told.

Another officer noted similarities with a truck bomb attack on the Federal Investigation Agency?s office in the eastern city of Lahore that killed 20 people in March. A civilian government led by Prime Minister Yousaf Raza Gilani was sworn in six months ago, after nearly nine years of rule by former army chief Pervez Musharraf, and is faced with the mounting militant challenge an economy on the verge of collapse.

?They want to destabilize the country. They want to destabilize the democracy. They want to destroy the country economically,? Gilani told journalists yesterday. Gilani also confirmed the death of the Czech envoy. Hospital officials said less than 20 foreigners had been wounded. Most were discharged.

The attack came hours after new President Asif Ali Zardari, widower of assassinated former prime minister Benazir Bhutto, made his first address to parliament a few hundred meters (yards) away, calling for terrorism to be rooted out. The tightly guarded hotel, part of a U.S.-based chain and popular with foreigners, diplomats and rich Pakistanis, was engulfed in flames for hours after the blast. Zardari made a televised address to the nation yesterday and said the bombing was cowardly. ?This is an epidemic, a cancer in Pakistan which we will root out,? he said. ?We will not be afraid of these cowards.?

Pakistan?s army is in the midst of a major offensive against al Qaeda and Taliban fighters in the Bajaur region on the Afghan border, while the United States has intensified attacks on militants on the Pakistani side of the border, infuriating many Pakistanis. ?The Army stands with the nation in its resolve to defeat the forces of extremism and terrorism,? army chief General Ashfaq Kayani said in a statement on Sunday. Militants have launched bomb attacks, most on security forces in the northwest, in retaliation for the strikes on them.

?They?re giving a very clear, unambiguous message that if the government pursues these policies, this is what (they) will do in response,? Talat Masood, a retired general and defense analyst, said of the attack. ?They are saying ?we can strike anywhere, at any time regardless of how good you think your security is?,? he said. An al Qaeda video, released to mark the seventh anniversary of the September 11, 2001, attacks in the United States, included a call for militants in Pakistan to step up their fight.

20-foot crater

Saturday?s attack was the worst yet in the capital. It came six months after a civilian government took power and a month after it forced U.S. ally Musharraf to step down as president. A crater up to 20 feet deep was in the road in front of the gates of the hotel, which had been bombed twice before. The Interior Ministry said the bomb probably contained more than 500 kg of explosives.

Flames and smoke poured out of the 290-room, five-storey hotel located in a high security zone. Dozens of cars were destroyed and windows shattered hundreds of meters away. Most people inside managed to flee before the fire spread, but a Reuters photographer saw a dead body lying on a top floor balcony yesterday morning.

Many of Islamabad?s expatriate community were considering leaving, having shrugged off earlier attacks in the city. ?I?ll be speaking to my boss tomorrow,? said Steve, a British man who has worked in Islamabad for a Pakistani firm for several years and did not want to use his full name. A wounded hotel security official said a truck had been stopped at the hotel?s security barrier and two small explosions had gone off minutes before the main blast. The Pakistani owner of the Marriott, said guards exchanged fire with the attacker before he set off the explosives at the gate.

Clemens Steinkanp, a German who was slightly wounded, said hotel security men had warned guests to move to the back of the building shortly before the bomb went off. ?Nothing happened for five minutes ... but then there was a huge blast,? he said. The United States, Britain and the U.N. secretary general condemned the bombing. Zardari, who won a presidential election this month, left for the United States yesterday, and is scheduled to meet Bush in New York on Tuesday before the U.N. General Assembly.