In last 24 hours, 21 militants have been killed during the Pakistani security forces operation in the country's tribal area of South Waziristan, according to an army press release Tuesday.

The security forces also arrested two suspects while one soldier lost his life and two others were injured in the operation.

On Oct. 17, the security forces launched the operation in the South Waziristan tribal agency bordering Afghanistan.

The army said that about 30,000 soldiers are in place to take on an estimated 10,000 hard-core Taliban militants in the lawless area. About 500 commandos arrived in the region on Friday.

The military said that the operation is launched in six towns of the area and is likely to continue for six to eight weeks.