Officials insisted attempts to "derail important democratic activity shall not succeed"
At least 128 people have been killed in a suicide bombing at an election rally in southwestern Pakistan.
Officials said another 150 people have been injured in the blast.
Election candidate Siraj Raisani was among those killed in the town of Mastung.
It comes amid growing tensions ahead of elections on July 25th.
The 'heinous attack' was condemned by the Pakistan Armed Forces, who also insisted attempts to "derail important democratic activity shall not succeed".
COAS condemns heinous terrorist attk in Mashtung. Grieved on loss of precious lives. Pak lost a highly devoted & capable politician Siraj Raisani. Attempts of inimical forces to derail important democratic activity shall not succeed. United we all Pakistanis shall IA defeat them.— Maj Gen Asif Ghafoor (@OfficialDGISPR) July 13, 2018
It's the most deadly attack in over a year in Pakistan and the third incident of election-related violence this week.
An earlier attack at a rally in the northern town of Bannu killed four people, BBC reports.
Separately, former Prime Minister of Pakistan Nawaz Sharif and his daughter Maryam have been arrested following their return from London.
Police made arrangements to whisk them away by helicopter to Adiala Prison in Rawalpindi on their arrival.
Mr Sharif has been sentenced to 10 years while his daughter Maryam was given seven years after corruption charges.
Pakistan's National Accountability Court ordered their arrest for failing to explain how the family acquired London properties.
The case came to light after the 2016 Panama Papers revealed that the apartments were bought through offshore companies.
Both Mr Sharif and his daughter have denied the corruption charges and have returned to Pakistan to challenge the order.
Mr Sharif was in London to be beside his wife, who is undergoing cancer treatment.
Thousands of supporters of Mr Sharif converged on Lahore International Airport to welcome him when his flight landed on Friday evening.