WANA, Sept 15: Tribal militants maintained pressure on security forces in different parts of South Waziristan for the seventh day on Wednesday.

Reports reaching here from the region quoted informed sources as saying that bodies of six soldiers and 11 wounded troops had been airlifted from Luddah Fort near the Makin bazaar, which has been under a security siege for several days.

Official sources here said the soldiers belonged to the 44 Baloch Regiment and were taken to Peshawar in two helicopters. It was not clear when and where the casualties occurred, but there are suggestions that these were linked to the Tuesday evening's ambush of a military convoy near Jandola.

An official of the Inter Services Public Relations (ISPR) in Peshawar denied the casualty report. Local sources said that four civilian tribesmen died in the Makin bazaar area as a result of shelling by troops.

Heavy exchanges of fire have been reported in the area and security forces and militants backed by volunteers of the Mahsud tribe were attacking each others' positions in Makin, Karwan Minza and Asman Minza.

The sources said that paramilitary forces had secured hill-tops around Makin and pounded suspected locations with heavy artillery. They said that several fortress-like mud-houses also came under attack.

Helicopter gunships were seen hovering over Wana, the regional headquarters of the agency, throughout the day. Meanwhile, tribal militant Abdullah Mahsud has claimed that his 'supporters' killed 15 troops and destroyed three vehicles during an assault on a military convoy in the Sarwekai area on Tuesday.

Talking to this correspondent on phone from an undisclosed place in the region on Wednesday, he said that a Punjab Regiment personnel had been captured during clashes in the Sarwekai area.

He identified the captured man as Mohammad Shaban. "The life of Mohammad Shaban is under threat if the government does not stop the military action in Waziristan," he warned.

Abdullah Mahsud, who was recently released from the US detention camp in Guantanamo Bay, earlier claimed that his supporters had captured 43 soldiers. This claim has been refuted by the ISPR.