At least three police officers and a candidate were killed during a protest against alleged rigging in the February 8 Pakistan polls in North Waziristan tribal district, state media has reported.

The state-run Pakistan TV reported on Saturday that supporters of former lawmaker Mohsin Dawar, who contested a constituency from North Waziristan, fired at an army camp in Miranshah, the district headquarters, killing three policemen.

According to local English daily Dawn, Dawar was also injured in a "firing incident" in North Waziristan.

Several political parties are protesting against alleged rigging in the crucial polls.

On Friday, at least two supporters of former Prime Minister Imran Khan's party were killed in the Shangla district of Khyber Pakhtunkhwa province during a clash with police when they were protesting against the alleged rigging in the election.