Pakistani security forces are on high alert as violence surged and claims of rigging mounted on the eve of elections.
Opposition allegations that the parliamentary polls will be rigged have also raised tensions and increased concerns among its foreign backers.
The death toll from yesterday's suicide bombing at a Pakistani election rally has risen to 46.
About 50 others remain critically injured, and are being evacuated to Peshawar from the northwestern town of Parachinar.
A security official said there had been initial confusion about the number of dead because bodies were so badly damaged in the attack.
The bomber attacked a Pakistan People's Party meeting outside the office of a local election candidate. The candidate's family said he was safe.
In further violence today four paramilitary soldiers were killed when a roadside bomb hit their vehicle in the southwestern province of Baluchistan.
Three police officials were wounded in a grenade attack on a polling station near the provincial capital Quetta.
Five people, including a candidate, were wounded in a grenade attack on the office of a pro-Musharraf party in Quetta city.
One person was killed and six others wounded when gunmen opened fire on an election office of a candidate for Mr Sharif's party in the eastern city of Lahore late today.
