At least 21 militants were killed in northwest Pakistan's Orakzai agency overnight as security forces continued targeting militants in the area on Saturday, army sources said.

The suspected militants were killed during clashes with troops in the Sangra area. Three militant hideouts were also destroyed.

Security forces claimed that they have cleared militants from the Sangra mountains in the agency. However gunship helicopters continued to target militant hideouts elsewhere in the agency.

Hundreds of militants have been killed in the area since the operation started in late March.

Orakzai has seen a growing number of Taliban and al-Qaida militants who fled the military operation in South Waziristan tribal area. Orakzai is the only tribal region which is not bordering Afghanistan.

Meanwhile one security personnel was killed in a landmine blast in tehsil Safi area of Mohmand tribal region, northwest of Pakistan, while one person was killed and three children injured when security forces were defusing a bomb in Bhambeer area of Pakistan-controlled Kashmir.