ISLAMABAD -- A suicide bombing at an election rally in Pakistan's tribal belt Sunday killed 46 people, a security official said.

"Now the death toll is 46. There are around 50 critically wounded people. They are being evacuated to Peshawar," the official told Agence France-Presse (AFP).

He said there had been initial confusion about the number of dead because bodies were so badly damaged in the Saturday attack. More victims also died in hospital from their wounds, the official said.

On Saturday, an interior ministry spokesman gave the toll as 37 after the attack in the northwestern tribal town of Parachinar, bordering Afghanistan.

Security officials earlier told AFP that the suicide bomber attacked a Pakistan People's Party meeting outside the office of a local election candidate. The candidate's family said he was safe.

Residents said the town was tense and streets were empty ahead of Monday's parliamentary elections.

Paramilitary soldiers had taken up positions in the town to control violence.

Angry supporters of the candidate on Saturday night burned down several shops and damaged some government buildings.