At least 29 people, including three policemen and two children, were martyred in a suicide blast outside a polling station near Eastern Bypass in Quetta on Wednesday, Civil Hospital spokesperson said.
Thirty-five others were injured in the attack at the Tameer-e-Nau polling station, which took place as millions of Pakistanis voted in the nationwide elections.
Rescue sources said the explosion occurred near a police vehicle on routine patrolling.
A police official said the suicide bomber wanted to enter the polling station.
"The suicide bomber blew himself up when police and FC personnel stopped him from entering the station," the official said.
Polling resumed in the polling station after being suspended briefly, however the number of voters remains low, the presiding officer said.
Balochistan Chief Minister summoned a report on the matter and instructed authorities to provide quality medical facilities to the injured. He also directed security agencies to beef up security in the province.
The border crossing between Pakistan and Afghanistan in Chaman, Balochistan was closed by the government on Tuesday for two days in the wake of the general election.
The province suffered the brunt of a series of attacks that killed more than 180 people across Pakistan during the brief but acrimonious election campaign, including a blast in Mastung district which martyred nearly 150 people including local politician Siraj Raisani.
He was one of three election candidates killed by militant attacks during the election campaign.
The military has stationed over 370,000 personnel nationwide to ensure security, bolstered by 450,000 police.