Islamabad: An Awami National Party leader contesting Pakistan's upcoming general election and his six-year-old son were gunned down outside a mosque in the southern port city of Karachi on Friday, police and witnesses said.
Sadiq Zaman Khattak, a candidate for polls to a parliamentary seat in Karachi, and his son were attacked by unidentified gunmen as they were leaving a mosque in Bilal Colony after Friday prayers.
The gunmen, who were riding a motorcycle, escaped after the attack.
Officials said five persons were injured in the shooting.
The Election Commission announced the postponement of polls in the constituency where Khattak was contesting.
No group claimed responsibility for the attack.
The shooting was the latest in a series of attacks targeting leaders and workers of the secular ANP, which has received threats from the banned Tehrik-e-Taliban Pakistan.
Senior ANP leader Bashir Jan had a narrow escape in a recent bomb attack in Karachi that killed 11 people.
Scores of ANP workers have been killed in attacks by the Taliban in the country's northwest.
The party has curtailed its election campaign following the latest attacks.
The Taliban has said it will target parties like the ANP, Muttahida Qaumi Movement and Pakistan People's Party, which were part of the last coalition at the centre, for their "secular policies" and for launching military operations against militants.
ANP chief Asfandyar Wali Khan condemned the attack on Khattak and said the three liberal parties were being targeted while others were holding election rallies.
Khan held the caretaker government and the Election Commission responsible for the murder of ANP candidates.
The killing of Khattak was also condemned by MQM chief Altaf Hussain, who said moderate parties were the target of terrorists.
Violence has spiked in Pakistan ahead of the May 11 general election, with some 60 people killed in attacks on politicians and political parties since last month.