In a fresh military operation at least 12 militants were killed while four others injured on Thursday in Pakistan's Orakzai tribal area.

According to Samaa TV, fighter jets bombed militants' hideout killing 12 militants and wounding four others as well as destroying four of their hideouts in Ghudagai area of Orakzai agency, adjacent to settled districts in northwestern Pakistan.

With Thursday's casualties the death toll on part of militants exceeded 600 in last one month and about two dozen security personnel have been killed in the fighting in Orakzai, one of the major bases of the Pakistani Taliban, the report added.

While, since mid-March over 1,000 militants were killed in the offensive in various parts of Orakzai.

The offensive in Orakzai came on the heels of an operation against the Pakistani Taliban in South Waziristan tribal area. Many militants in South Waziristan were believed to have fled to Orakzai,though the top Pakistani Taliban leaders are believed to be in North Waziristan, the TV report added.

For months, the military pounded Orakzai with air strikes, eventually staging a ground operation as well. The offensive intensified in March, with the reported daily death tolls of suspected militants sometimes in the dozens.

Pakistani troops launched two major offensives in the Swat valley and in the militant bastion of South Waziristan on the Afghan border last year to root out militants.