Unidentified gunmen on Friday opened fire at a vehicle carrying a Pakistani politician during an anti-government rally in which at least 12 people were wounded, media reports said.
The incident took place around noon in Sanghar town in Sindh province, Xinhua reported.
The gathering was held to protest a local government body ordinance passed by the Pakistan Peoples Party-led provincial government.
The gunmen fired when protesters forced people to close shops, witnesses said. The PML-F leader was said to be safe but his son was reportedly injured.
No group claimed responsibility for the attack.
The PML-F is a Sindh-based party that won five seats in 2008 in the National Assembly, the lower house of parliament.