At least 18 Afghanistanian soldiers have been killed by Taliban militants in Afghanistan’s western province of Farah.

Local officials said on Saturday that the overnight attack was carried out in Bala Buluk district, setting off a fierce gun battle.

Afghanistanian Defense Ministry spokesman Dawlat Waziri said four soldiers had been killed but the head of the local provincial council, Farid Bakhtawar, said the death toll had reached 18.

He added that around 25 militants were killed in the battle.

Shortly after the ambush, Taliban spokesman Zabihullah Mujhaid claimed responsibility for the attack.

In recent months, Farah province has witnessed an increase in attacks by militants against security forces. Local officials have called for the deployment of more forces in the province.

The rise in attacks by Taliban over the past months has raised doubts about the effectiveness of Washington’s strategy in Afghanistan some 17 years after the United States and its allies invaded the country under the pretext of war on terror.

A new study has found that Taliban militants are openly active on 70 percent of Afghanistan’s soil, fully controlling four percent of the country and having presence in another 66 percent.