Islamabad (PTI): Two US marines were among the four foreigners killed in the devastating suicide attack on the Pakistani capital's Marriott hotel as rescue workers today completed the search of the gutted multi-storied luxury hotel, saying there was no possibility of finding any more survivors.

A suicide bomber rammed a truck packed with 600 kg of military grade explosives into the main gate of the Marriott on Saturday evening killing 53 people.

A US embassy official here confirmed that the two employees of the US defence department were among the dead and that a third American, who was a contractor for the state department was unaccounted for.

He said three other US embassy employees and a contractor were injured. The bomb attack also claimed the life of the Czech Ambassador to Pakistan.

The hotel was packed with foreigners and Pakistanis who had gathered for the iftar meal to break the traditional fast during the holy month of Ramzan when the attack took place.

A total of 266 people were injured in the attack, described as the biggest bombing ever in Pakistan's history.

Rescue workers today said they had completed their search in most parts of the five-storey, 290-room hotel that was a favourite gathering spot for Westerners and the Pakistani elite. They said there was no possibility of any more bodies being found in the blackened structure.