Islamabad - A suicide attacker killed at least three troops and injured three more Monday at an army check post in Pakistan's restive north-west Swat valley, a local military spokesman said.

"A suicide bomber rammed his explosive-laden vehicle into the post at around 11:45 am in Gashkor village of the district," Colonel Nadeem Ahmad told Deutsche Presse-Agentur dpa.

The post was completely destroyed in the attack, he said.

According to the spokesman, helicopter gunships were targeting militant positions in the Kabal area of Swat, where government forces have been battling the followers of a radical cleric Maulana Fazlullah for more than a year.

"We have some reports of casualties on the militants' side in the strikes but the numbers are yet to be ascertained," the spokesman said.

Fazlullah waged an armed struggle late 2007 to enforce Taliban rule in Swat valley, which used to be a popular tourist destination.

Islamabad dispatched troops to quell the rebellion, but peace has not been restored in the region. (dpa)