Islamabad, Aug 22 (IANS): Pakistani forces have killed 52 terrorists and wounded 31 others in an offensive in a mountainous region in the Khyber tribal region, the military said on Monday.

The forces had launched the major ground and air offensive in Rajgal valley in Khyber in northwestern Pakistan bordering Afghanistan in July to clear the rugged and difficult terrain of the terrorists who use the area for cross-border movement.

Military spokesman Major General Asif Ghafoor told a press conference in Rawalpindi that in the operation codenamed "Khyber-4" the army has cleared the area and the terrorists can no longer use it to cross the border.

The spokesman said that 52 terrorists have been killed and 31 injured while four surrendered in Rajgal and Shawal area in North Waziristan during the operation.

"Ground targets have been achieved in Rajgal and Shawal due to the planned, integrated and effective operation against the terrorists," he said.

Major Gen Ghafoor said that the security forces have also defused hundreds of landmines during "one of the most difficult operations".

He said that two soldiers lost their lives and 15 were injured during the operation, adding the army has also set up 91 checkposts in Rajgal valley for permanent security presence in the valley.

The army had earlier stated that the operation in Rajgal Valley aimed at breaking contacts between the Islamic State militants and Pakistani militants, and stopping the IS from entering Pakistani areas from Afghanistan.

The spokesman said the Pakistani forces have conducted operations against all terrorist groups, including the Haqqani network.