Benazir Bhutto yesterday received a new death threat, her lawyer said, as a top official revealed there were apparently two suicide bombers behind last week's bloody assassination attempt.

Senator Farooq Naik, Bhutto's lawyer, said he had received a two-page handwritten letter in the Urdu language from an unidentified person threatening to kill her "by any means". The writer claimed to be a friend of al-Qaida, Osama bin Laden and extremists in Pakistan.

The authenticity of the letter could not be confirmed, but Naik said the party was taking it seriously. He said he asked the chief justice of Pakistan to get the government to investigate the threat and protect her.