Two bomb explosions near the offices of the candidates in the Pakistani province of Balochistan killed at least 27 people and wounded dozens on the eve of general elections, officials said.
The first blast killed 18 people in the north of Quetta city.
A second explosion killed nine people in Qila Saifullah, about 150km (93 miles) to the east.
The vote has been tainted by violence and claims of poll-rigging. Former PM Imran Khan is barred from contesting.
Police are working diligently to unravel the cause of the two blasts.