Two suicide bombers have killed 132 people including a political candidate, as violence continues before Pakistan heads to the polls.

Friday’s attacks were the deadliest in Pakistan’s troubled election campaign and took place just before disgraced Nawar Sharif was arrested on his return to the country.

A suicide bomber killed 128, including candidate Siraj Raisani, in the southwest region of Baluchistan, while four others died in a strike in the northwest.

The strike was targeting candidate Akram Khan Durrani, who escaped unhurt, but 20 others were wounded.

Mr Durrani is running against popular former politician Imran Kan and is a candidate of Muttahida Majlis-e-Amal, an election alliance of radical religious groups.

He may have been targeted amid ongoing allegations that Mr Sharif is being kept out of politics to allow the military to maintain power.

Mr Khan condemned the attack on his rival, tweeting: Strongly condemn the terrorist attack on Akram Durrani & his convoy.

There seems to be a conspiracy to sabotage the 25 July elections but the people of Pakistan will not allow any design intended to target these historic elections to succeed.

:: Former Pakistani PM Nawaz Sharif and daughter arrested as more than 100 die in bombing

The attacks came hours before Sharif returned with his daughter Maryam, to face 10 years in prison on corruption charges.

Maryam Sharif faces seven years in jail.

He was taken into custody but is expected to appeal his sentence and seek bail.

Mr Raisani was killed when a suicide bomber blew himself up at a rally amid scores of supporters.

Islamic State claimed responsibility for the attack in a statement to its news agency, but gave no reason for bombing Mr Raisani.

He was running for election for the Baluchistan Awami Party and is the brother of the former chief minister, Aslam Raisani.

Caretaker home minister Agha Umar Bungalazi said 300 people were wounded in the bombing.

Mr Sharif flew into Lahore from London, where he was visiting his ailing wife when he was convicted of corruption.

His son-in-law is currently serving his one year prison sentence on the same charge, which stems from the purchase of luxury apartments in Britain, which were found to have been bought with illegally acquired money.

Police swept through Lahore arresting Mr Sharif’s supporters, who turned out to greet them at the airport.

Barricades and barbed wire were placed across roads toward the airport to prevent crowds.

Mr Sharif has been banned from participating in politics, and his brother Shahbaz is now the head of the Pakistan Muslim League, running for re-election on 25 July.

Mr Sharif has encouraged people to continue supporting the party and said he is not afraid of prison.

(c) Sky News 2018: Suicide bombers kill 132 including political candidate in Pakistan election violence