KARACHI, October 23, SPA -- Two suicide bombers wereapparently behind the bloody assassination attempt onBenazir Bhutto and investigators are trawling Pakistan'snational identity card database to establish theiridentities, a top official said Tuesday. Sindh provincial Gov. Ishrat Ul-Ebad Khan said people incustody in connection with seven previous suicide attacksin Karachi were being questioned in prisons in the city andelsewhere in Pakistan in the hope they can provide cluesinto Thursday's bombing that killed 136 people. Police had initially said only one suicide bomberparticipated in the attack, but Khan said «it was morethan likely» there were two, after pieces of a secondsevered head were found at a hospital and at the site ofthe attack. He said the state agency that oversees Pakistan's nationalidentity cards was helping to try and identify the bombers_ one of whose pictures has been made public. Although no arrests have been made, Khan said theinvestigation was progressing. He rebutted earlier reportsthat three men had been detained in connection with avehicle used by an attacker, the Associated Press reported. Bhutto's spokeswoman reiterated a call for the chiefinvestigator to be replaced. She has already called forPakistan to seek expert help from the U.S. and Britain inthe probe. «Benazir Bhutto is not satisfied with the investigation,comments made by some elements of the government blaming(Bhutto's Pakistan People's Party) are increasing herconcerns,» spokeswoman Sherry Rahman said. Bhutto escaped unhurt from the bombing that targeted herheavily guarded convoy in the southern city of Karachiaround midnight, about 10 hours after she returned toPakistan from an eight-year, self-imposed exile.--SPA www.spa.gov.sa/492696