Nine soldiers have been killed as the Taliban stormed a security post in Afghanistan's western Farah province late Tuesday night, an official said.

"Four others are injured," Farah provincial spokesman, Naser Mehri told dpa, adding that the incident happened in Poshtrod district.

The attack was repelled by fresh troops and the air support, Mehri added.

Seventeen insurgents have been killed and several others injured in the clash between the militants and Afghan security forces, Mehri claimed.

The attack took place Tuesday night. The intense, four-hour gun battle included the use of artillery against the army.

Nightly attacks on security posts and bases are on the rise, and in the past few months have become a weekly if not daily occurrence.

Last Thursday a Taliban attack on a military compound left 43 soldiers lead in southern Kandahar province.

While the fighting intensifies across the country, Afghan security forces are becoming increasingly overwhelmed and demoralized. This contributed to the decision by the U.S. and NATO to increase the number of international troops in Afghanistan.

Many of the additional soldiers are supposed to support the training of the Afghan army and police.