Karachi: A large number of voters turned up for a high-profile by-election for a National Assembly seat in Karachi where former premier Benazir Bhutto's party is pitted against the Muttahida Qaumi Movement (MQM), which is a key partner in the ruling coalition.

Police and government officials said the polling for the National Assembly seat 250 comprising key areas of Karachi including Clifton, Defence Housing Authority and Delhi Colony was peaceful barring a few minor incidents between the MQM and Pakistan Peoples Party (PPP) supporters.

PPP's Nafees Siddiqui is running against MQM's Akhlaq Hussain Abidi for the seat which fell vacant after the death of Abdul Sattar Afghani of the Muttahida Majlis-e-Amal (MMA).

The Islamic parties alliance of MMA is boycotting the polls, paving the way for the one-to-one contest between the PPP and the MQM.

All major opposition parties, including Pakistan Muslim League (Nawaz), the Awami National Party and Sunni Tehreek, are supporting PPP.

PPP has accused the MQM supporters of rigging and violence and said President Pervez Musharraf's current visit to the city is to influence the polls. "Even the car of Nafees Siddiqui was attacked and damaged by MQM supporters at a polling station near Haqqani Chowk, Burns Road," Sherry Rehman, PPP spokesperson, told reporters.