Pakistan says it has sealed its border with Afghanistan and set up 763 guard posts to prevent any militant infiltration into Afghanistan before Sunday's Afghan parliamentary polls.

Lieutenant General Safdar Hussain told reporters that an overnight curfew has been imposed, and troops have been given orders to shoot on sight anyone found within five kilometers of the border.

General Hussain also said his men have busted the biggest al-Qaida base in the North Waziristan tribal zone and recovered a huge cache of weapons as part of operations linked to preventing disruption of the Afghan election.

He says the militant den was in a madrassa, or Islamic seminary, and a nearby compound owned by the son of Taliban commander, Jalaluddin Haqqani. He said the commmander's son, Sirajuddin Haqqani, escaped after a tip-off.

He said Pakistani troops recovered 15 truckloads of ammunition and weapons. In all, 28 militants were captured.

Some information provided by AP and AFP.