A suspected suicide blast at a rally by slain opposition leader Benazir Bhutto's party in Pakistan's tribal belt on Saturday killed at least 21 people, medical officials said.
"Twenty-one people died and 93 were injured. It's a very severe emergency, a lot of the wounded are in a critical condition," a doctor at the main hospital in the tribal town of Parachinar told AFP.
An AFP correspondent at the hospital said he had counted at least 21 dead bodies.
The attack in Parachinar, the main town in the troubled Kurram tribal district bordering Afghanistan, heightened fears for the security of general elections being held in two days' time.
"It appears that a suicide bomber attacked a Pakistan People's Party meeting outside the party office in Parachinar," a security official told AFP on condition of anonymity.
Earlier, a security official said up to 20 people were feared dead, adding that the blast had happened outside the office of local PPP candidate Riaz Hussain.
One witness said a man in a car drove up to a meeting and the vehicle then exploded. Officials could not immediately confirm the account.
Former premier Bhutto was killed by a suicide and gun attack in the garrison city of Rawalpindi on December 27, sparking mass riots and forcing the postponement of elections by six weeks.
Pakistan has been hit by further suicide bombings and bomb blasts in the run-up to the elections due on Monday. (AFP)
Pakistan vote blast kills 21, wounds 93