Nawabzada Siraj Raisani, a political candidate for the Balochistan Awami Party, was also killed in the latest attack in the run-up to Pakistan's July 25 general elections.

At least 128 people were killed by a suicide bomber at a political rally in Pakistan's Mastung district on Friday, including candidate Nawabzada Siraj Raisani, provincial Health Minister Faiz Kakar told DawnNewsTV.

The attack, which also injured a further 150 people, 12 of them critically, is the deadliest bombing in Pakistan since 2014, according to the BBC. No group has yet claimed responsibility.

Victims were transferred to the Civil Hospital Quetta, Bolan Medical Complex and Combined Military Hospital Quetta, according to Kakar.

Witnesses said the attacker targeted a meeting organized by Siraj Raisani, a Balochistan Awami Party (BAP) candidate for the PB-35 Matsung district.

"Mr. Siraj Raisani succumbed to his wounds while he was being transferred to Quetta," said provincial Home Minister Agha Umar Bungalzai.

This is the latest in a string of attacks on political candidates in the lead up to the country's July 25 general elections.

Earlier on Friday, a bomb explosion targeted a convoy carrying former Khyber Pakhtunkhwa Chief Minister Akram Khan Durrani in Pakistan's Bannu district. Four people were killed and 32 more were injured. Durrani survived the attack.

Two people were injured in another bomb blast detonated near the BAP's election office in Khuzdar late Thursday.

On Wednesday night, a bomb exploded in Peshawar killing 21 people, including Barrister Haroon Bilour, leader of the Awami National Party (ANP). Local police said the attack, which used approximately eight kilograms of TNT, was claimed by the outlawed Tehreek-i-Taliban Pakistan (TTP). Another 75 people were injured.

Despite the latest attack, ANP officials said the party would not back down from contesting the upcoming general elections. Bilour was a candidate for the provincial assembly seat.