Four militants, including a Taliban key commander Mullah Janat Gul, were killed by security forces in Afghanistan's Balkh province on Tuesday, the police said."The government forces, acting upon intelligence reports, targeted a hideout of Taliban rebels in Dawlatabad district, killing the notorious commander along with three of his men on the spot," a police official told Xinhua news agency.Janat Gul's death could prove a major setback to the Taliban insurgents in Dawlatabad and adjoining areas, said the official.Security forces launched operations in Dawlatabad district on Monday and the strikes would last until the area gets cleansed of insurgents, the official said.