A bomb exploded next to a convoy of the deputy chairman of the Pakistan Senate on Friday in the violence-plagued province of Baluchistan, killing at least 25 people, officials said.

At least 35 people were wounded in the blast near the town of Mastung, 50 km (30 miles) from the provincial capital of Quetta. Television footage showed a vehicle mangled by the blast.

Senator Abdul Ghafoor Haideri, the deputy chairman of the upper house of parliament, told Reuters minutes after the explosion he believed he was the target and he had sustained minor injuries.

"There are many casualties as there were many people in the convoy," he said by telephone.

There was no immediate claim of responsibility for the attack from the many militant groups operating in Baluchistan.

Haideri is a member of Jamiat e Ulema Islam, a right-wing Sunni Islamist political party that is part of Prime Minister Nawaz Sharif's coalition government.

District health official Sher Ahmed Satakzai said the death toll had risen to 25 and 10 were in critical condition in hospital.