MIRAMSHAH: At least 23 suspected militants were killed late on Wednesday during a clash with security forces in the country's troubled northwest, officials said.

According to a security official who requested anonymity, the suspected militants tried to ambush a convoy of security forces which was returning back from Khajuri checkpost area in Mirali Tehsil of North Waziristan tribal region.

The convoy had gone in the area to rescue soldiers who were injured in a suicide bomb attack yesterday.

Security forces retaliated with gunfire and encircled the suspects inflicting heavy casualties.

The gun-battle continued for several hours during which the 23 suspected militants were killed.

Moreover, three security personnel were also injured in the clash.

A search operation was underway in the area.

The clash follows a suicide attack on a military checkpoint which killed at least five soldiers and wounded 34 others. The attack had taken place while the security men were offering prayer in a mosque at the post.

Tehrik-i-Taliban Pakistan (TTP) spokesperson, talking to Dawn.com, claimed that the militant group was behind the suicide attack and that it was carried out to avenge ex-TTP chief Hakimullah Mehsud's death.

North Waziristan, one of the seven tribal districts along the Afghan border, is a hotbed for Al Qaeda and TTP militants.

The TTP has led a bloody campaign against the Pakistani state in recent years, carrying out hundreds of attacks on security forces and government targets, mainly in the country's northwest.