RAWALPINDI, Feb 12 A United Nations' commission probing the assassination of former prime minister Benazir Bhutto interviewed former City Police Officer (CPO) Saud Aziz and Senior Superintendent of Police (Operations) Yasin Farooq here on Friday, sources said.

On December 27, 2007, the two police officers were at the site of the suicide gun-and-bomb attack which killed Ms Bhutto and several Pakistan People's Party supporters.

The UN team first questioned SSP Farooq, who was tasked with overall supervision of Ms Bhutto's election rally at the Liaquat Bagh.

Later the investigators went into a two-hour session with Saud Aziz, who is presently posted as the police chief in Multan, the hometown of Prime Minister Yousuf Raza Gilani.

According to the sources, the UN team questioned CPO Aziz about the security plan and the circumstances under which the crime scene was washed immediately after the attack.

Two of the UN team members are likely to visit Lahore on Saturday to interview the then Punjab governor, Khalid Maqbool.