District police chiefs in Punjab province were directed to take steps to counter al-Qaeda’s plans to target Bhutto’s top aides, including her security advisor Rehman Malik, police sources were quoted as saying by Geo news channel.

The sources also said al-Qaeda-linked Pakistani Taliban groups had been directed to target retired judge Syed Ibn Ali, a PPP candidate for next month’s general election, and his son.

Bhutto was assassinated by a suicide attacker after an election rally in Rawalpindi on Thursday.

The Pakistan government blamed al-Qaeda and Pakistani Taliban commander Baitullah Mehsud for carrying out the attack but Mehsud has denied involvement in her assassination.