FARAH, Afghanistan, May 28 (Xinhua) -- Four militants were killed and two narcotics labs were destroyed following a special anti-narcotics operation in Afghanistan's western province of Farah overnight, local police said Tuesday.

"The operation was launched by army commandos and a special unit of national police in Seyyajangal locality of Bala Buluk district Monday night," provincial police spokesman Muhibullah Mubhib told Xinhua.

Those among the slain terrorists were two foreign militants and the security forces also destroyed a militants' vehicle at the site, he said.

The province has been the scene of heavy clashes between security forces and militants for long.

In 2018, some 6,400 tons of opium was produced in Afghanistan particularly in western and southern parts of the country, where the government security forces have little presence, according to official figures.