ISLAMABAD, July 14 (Xinhua) -- Death toll of a suicide blast hitting a campaign rally in Mastung area of Pakistan's southwest Balochistan province on Friday has mounted to 128 till Saturday morning, officials said.

Confirming the death toll, caretaker home minister of Balochistan province Agha Umar said that over 120 people also got injured in the deadly blast.

Spokesperson of the provincial government announced a two-day mourning during which the national flag will fly at half mast at all government buildings.

Qaim Lashari, deputy commissioner of Mastung, said that target of the explosion was political leader Nawabzada Siraj Raisani, who was attending the campaign rally in his constituency Mastung.

The leader, who lost his teenager son in 2011 to terrorism, was shifted to a hospital in provincial capital of Quetta where he succumbed to injuries.

Police said that the bomber blew himself up in a compound where local leaders were addressing the public and senior leaders including Raisani were sitting at the stage.

The attack happened shortly after Raisani, a candidate of Balochistan Awami Party vying for a seat in the provincial assembly, reached at the site to attend the meeting attended by over 1,000 people, local TV channel Geo reported.

The injured people were shifted to hospitals in Mastung and Quetta where a state of emergency was declared by the provincial government.

Local media quoted hospital sources as saying that most of the bodies have been handed over to the relatives. However, a few are still lying in the mortuaries of the hospitals for being too mutilated to be identified.

Terrorist group of Islamic State claimed the attack at its website.

The country's President Mamnoon Hussain, caretaker Prime Minister Nasir-ul-Mulk and army chief Qamar Javed Bajwa condemned the attack.

Friday's attack was the third and the deadliest attack during the recent spate of terrorist attacks targeting political leaders who are busy in holding meetings and addressing public gatherings ahead of general elections to be held in the country on July 25.

The attacks left about 150 people killed and over 200 injured during the last four days.