At least 20 people have been killed and more than 12 others left injured during a militant attack on a security checkpoint in northwestern Pakistan, local security officials say.
According to the sources, dozens of armed militants attacked a security checkpoint in South Waziristan Agency on Thursday, killing eight security forces and injuring 12 others, a Press TV correspondent reported.
Just after the attack, Pakistani security forces killed 12 militants and injured several others, the report said.
The checkpoint was also completely destroyed in the Thursday attack.
Militant attacks have sharply increased in Pakistan after the US claimed in early May that its forces killed al-Qaeda leader Osama bin Laden in the Pakistani town of Abbottabad.
The US operation has severely strained relations between Washington and Islamabad.
The Pakistani parliament recently passed a resolution condemning the US attack in Abbottabad and demanding a review of ties with the United States and other Western countries.
The resolution also called for an independent investigation into the attack, which the parliament called a unilateral action and a violation of Pakistan's sovereignty.
The resolution said the repetition of such attacks could have dire consequences for peace and security in the region and the world.