Article published on the 2008-09-03 Latest update 2008-09-03 10:29 TU
No-one is reported to have been injured or wounded in the shooting, which hit the bullet-proof window of a car in Gilani's motorcade.
Gilani had been working in support of Benazir Bhutto's widower Asif Ali Zardari who will stand in the country's presidential election, which takes place on Saturday.
Earlier, North West Frontier Province Governor Owais Ahmed Ghani accused international forces based in Afghanistan of violating Pakistani territory and killing civilians in a cross-border raid.
"At least 20 innocent citizens of Pakistan including women and children were martyred," he said. "This is a direct assault on the sovereignty of Pakistan and the people of Pakistan expect that the armed forces of Pakistan would rise to defend the sovereignty of the country."
The Nato-led International Security Assistance Force in Afghanistan said that it is not aware of any such operation.