Islamabad - Rescuers found more bodies from the gutted Marriott Hotel in the Pakistani capital Sunday, increasing the official death toll to 53 in one of the country's worst suicide bombings, officials said.

A raging fire that completely destroyed the six-storey building held back rescuers through the night, before they could conduct room- to-room searches for survivors or victims.

Pakistani Prime Minister Yousaf Raza Gilani put the official death toll at 53, as rescue personnel searched through the charred remains of the hotel.

Inquiring after the blast victims in one of the several hospital's in the capital where the wounded were taken, Gilani confirmed that Czech Ambassador Ivo Zdarek was among the dead.

A truck loaded with around 1 ton of explosives Saturday evening rammed into the security barrier of the luxury hotel which was packed with hundreds of guests. The huge blast left a crater more than 6 metres deep and 9 metres wide.

The explosion shattered the windows of buildings and damaged structures near the hotel, which is located less than a kilometre from the residences of the prime minister and president.

The hotel was frequented by diplomats, foreigners and influential Pakistani figures.

An American national has also been confirmed dead, while several foreigners, including three Germans, were injured.

About 260 people were injured, dozens of them foreigners.

No one has claimed responsibility for the deadly attack but Taliban militants based in Pakistan's tribal areas and the al-Qaeda terrorist organization are suspected.

Media reports cited unnamed police officials as saying that a group of 30 US Marines, who were allegedly part of a security team for this week's visit of Admiral Mike Mullen, chairman of the US Joint Chiefs of Staff, might have been the intended targets of the attacker.

The US personnel were scheduled to leave for Afghanistan on Sunday morning, the private Urdu-language Aaj television channel said.

English-language daily News claimed a lawmaker from the ruling Pakistan People's Party, Mumtaz Alam Gilani, protested to the hotel management when he witnessed the US troops inside the hotel late Wednesday.

He warned that the security of the hotel was being endangered and vowed to raise the issue in parliament.

Hotel owner Sadruddin Hashwani said 39 victims, including three foreigners, were staff members. He vowed to fully renovate the hotel within four months.

Islamabad police chief Asghar Raza Gardezi said investigators were investigating what type of explosive was used in the bombing, but rain at the blast site was raising fears that vital evidence might be lost.

President Asif Ali Zardari condemned the attack in a brief televised address to the nation early Sunday. "Terrorism is an epidemic, a cancer which we will eliminate at all costs," he said.

He called Pakistani a brave nation that would not be cowed by terrorist acts. "Pakistanis consider their lives a trust of Allah Almighty and have no fear of death as its day is fixed," he said.

Similar condemnations came from the international community. US President George W Bush said it was "a reminder of the ongoing threat faced by Pakistan, the United States, and all those who stand against violent extremism."

A statement from the European Union presidency, currently held by France, said the EU would "more than ever stand side by side" with Pakistan in its struggle against terrorism. (dpa)