Hafiz Naeem ur Rehman speaks during an interview with the media in Karachi, Pakistan. Reuters

A senior Pakistani politician who won provincial elections in the commercial hub of Karachi last week has given up his seat saying the vote was rigged in his favour.

Pakistan voted in national and provincial elections on Feb. 8 but the polls were marred by accusations of rigging to defeat independent candidates backed by jailed ex-prime minister Imran Khan.

The caretaker government and Pakistan's election commission have rejected the allegations and said the country has laws and systems to investigate specific complaints.

Hafiz Naeem ur Rehman of the Islamist Jamaat-e-Islami party was declared winner of provincial seat 129 in Karachi after securing more than 26,000 votes.

Supporters of Hazara Democratic Party take part in a sit-in protest amid claims of alleged vote-rigging in Quetta. AFP

But Rehman said he discovered that votes cast for Khan's Pakistan Tehreek-e-Insaf (PTI) party-backed independent candidate Saif Bari were reduced to 11,000 from 31,000 when records of votes polled at individual polling stations were tabulated.

Khan is in jail over corruption and criminal charges after he fell out with the country's powerful military and his PTI was barred from contesting elections, forcing members to stand as independents. The military denies meddling in politics.

"Public opinion should be respected, let the winner win, let the loser lose, no one should get anything extra," Rehman told Reuters on Wednesday.

Supporters of PTI party block the road as they protest against the alleged rigging election results in Peshawar. AFP

"I will not accept it, the winner should be given the victory."

Saif Bari could not be reached for comment and the PTI said it needed time to respond. The election commission did not immediately respond to a request for comment.

Reuters