The convoy was attacked near Miran Shah, the main town in North Waziristan tribal area, a Miran Shah-based intelligence official said on condition of anonymity because of the secretive nature of his job.

Security forces backed by at least three helicopter gunships fired at suspected militant positions in Miran Shah and a nearby village after the convoy came under rocket attack, he said.

There was no word on any militant casualties.

Gunfire rang out in Miran Shah and shops in the town closed and streets were deserted after troops deployed there fired toward militants, an Associated Press reporter in Miran Shah said.

Miran Shah has been the scene of intense clashes between security forces and local tribal militants earlier this year.

Late Saturday, suspected Islamic militants fired assault rifles at a roadside military post in North Waziristan, a second intelligence official said yesterday.

Troops retaliated against the attack, firing machine guns in the direction from which the assault came, but it was not known whether the attackers suffered any casualties, the official said on condition of anonymity.

Suspected local and foreign Islamic militants - allegedly linked with the Afghan Taliban militia and al-Qaida - have been blamed for a steady stream of attacks on security forces in North Waziristan in recent months.

On Friday, two suicide attackers detonated an explosives-laden car near a military convoy on a road linking Miran Shah, North Waziristan's main town, with the nearby city of Bannu, killing four soldiers and wounding seven, officials said.