Thirty militants were killed and 10 paramilitary personnel injured in a major attack by insurgents on a check-post in Pakistan's troubled region of north Waziristan.

The fighting in the region comes hours after the army's gunship helicopters bombed positions of the militants at the border of north and south Waziristan on Wednesday, killing 40 militants.

Army spokesman Maj Gen Waheed Arshad said that only 10 soldiers were injured in the attack, even as the local TV channels claimed that 10 paramilitary soldiers and 30 militants were killed in the clashes.

The fighting which erupted in Makeen on Wednesday night continued till Thursday morning, he said.

Meanwhile, a spokesman of the militants denied Wednesday's army version.

"The Inter Services Public Relations claim is otally baseless and the mujahideen are safe," Ahmadullah Ahmadi, was quoted as saying by The Dawn, who identified himself as a spokesman for militant commander Hafiz Gul Buhadur based in Miramshah.

The newspaper quoted officials as saying that a group of militants launched an offensive against security forces in Shawal region.

Ahmadi said that militants had kidnapped 11 FC men from the Bannu Frontier Region.

The first attack was carried out in Pesh Ziarat area and security forces called in Cobra helicopters from Miramshah.

Officials said the helicopters targeted positions in Shawal and about 40 militants were killed. Combat helicopters shuttled between Shawal and Miramshah.

The militants later moved towards Nowaz Kot in Makin area of South Waziristan and attacked personnel of the Bajaur Scouts who had set their base in a school on Wednesday.

Militants also attacked a paramilitary base in the Razmak area of North Waziristan with rockets and other heavy weapons. The security forces fired artillery from the fort, which also houses a cadet college.

Meanwhile, another spokesman for the militants warned that they would begin killing more than 200 soldiers who had surrendered in South Waziristan nearly two weeks ago.

"We will start killing them in batches of three soldiers if the military operations did not stop," spokesman Zulfiqar Mehsud said.

The army has been battling militants in the Waziristan region for nearly four years.