The death toll in a suicide bombing in southwestern Pakistan Friday jumped to 85, an official said, the deadliest in a string of attacks on political rallies that have raised security fears ahead of nationwide polls on July 25.
The blast in the town of Mastung, near the Balochistan provincial capital Quetta, came hours after another bomb killed at least four people at a campaign rally in Bannu in the country's northwest.
The attacks underscored the fragility of Pakistan's dramatic improvement in security and raised fears ahead of the vote.
"Death toll has risen to 85," Balochistan health minister Faiz Kakar told AFP, adding that were more than 100 wounded.
Earlier he had said 70 people were killed.
According to senior provincial official Saeed Jamali, the bomber detonated in the middle of a compound where a political meeting was taking place. Another senior official, Qaim Lashari, also confirmed it had been a suicide blast.
The explosion killed Siraj Raisani, who was running for a provincial seat with the newly formed Balochistan Awami Party (BAP), provincial home minister Agha Umar Bungalzai told AFP.
"Mir Siraj Raisani succumbed to wounds while he was being shifted to Quetta," he added. Raisani was the younger brother of former provincial chief minister Mir Aslam Raisani.
The explosion comes hours after four people were killed and 39 injured when a bomb hidden inside a motorcycle detonated near a Pakistani politician's convoy in Bannu on Friday, near the Afghan border.
The earlier bomb was targeting the convoy of the Muttahida Majlis-e-Amal (MMA) candidate Akram Khan Durrani, who survived the attack, police said. No group has yet claimed responsibility.
On Tuesday, a bomb claimed by the Pakistani Taliban targeted a rally by the Awami National Party (ANP) in the city of Peshawar.
Local ANP leader Haroon Bilour was among the 22 killed. Thousands flocked to his funeral the next day.
'Duty to protect'
Following the series of attacks, activists called for Pakistani authorities to remain vigilant to protect candidates during the final days of the campaign season.
"The Pakistani authorities have a duty to protect the rights of all Pakistanis during this election period -- their physical security and their ability to express their political views freely, regardless of which party they belong to," said Omar Waraich, deputy South Asia director at Amnesty International.
The military has warned of security fears in the run-up to the tense election on July 25, and said it will deploy more than 370,000 soldiers on polling day.
Militants have targeted politicians, religious gatherings, security forces and even schools in Pakistan.
But security across the country has dramatically improved since government and military operations cleared large swathes of territory near the Afghan border in recent years.
Analysts warn however that Pakistan has yet to tackle the root causes of extremism, and militants retain the ability to carry out attacks.
Last month a drone strike killed the leader of the Pakistani Taliban, Maulana Fazlullah, in neighbouring Afghanistan in what the Pakistani army called a "positive development" that also sparked fears of reprisals.