The bomber struck in Badabher area of Peshawar just after Khushdil Khan, Deputy Speaker of the Khyber-Pakhtunkhwa province, left a cemetery after attending the funeral prayers for a local resident, the police said.
Khan, a vocal critic of the Taliban, was the target of the bomber but he escaped unhurt as he left the area 10 minutes before the blast, Peshawar police chief Imtiaz Altaf told reporters.
Officials at the Lady Reading Hospital said they had received 13 bodies and 32 injured. Several of the wounded were in a serious condition and the death toll could rise, they said.
The police said they had found the legs and head of the suicide bomber. They said most of the casualties were caused by ball bearings packed into the attacker's suicide vest.
Several vehicles were damaged by the powerful blast.
Security forces cordoned off the area and launched a search operation. No group claimed responsibility for the attack.
Badabher has a strong anti-Taliban 'lashkar' or private militia that supports the security forces against militants. It was not clear if any leader of the militia was attending the funeral. This was the second terror attack in Badabher in less than two months. On February 2, a car bomb went off in a busy market in the area, killing at least nine persons and injuring 24 others.
Khyber-Pakhtunkhwa province has witnessed a surge in violence by the Pakistani Taliban in recent weeks.
On Friday, a Taliban spokesman had warned that the militants would carry out suicide bombings against security forces and the government across the country if the family of slain Al Qaeda leader Osama bin Laden is not released.For Rediff Realtime News click here