MAZAR-E-SHARIF, Afghanistan, Jan. 4 (Xinhua) -- Three militants affiliated with the Taliban outfit were killed as their explosive device went off prematurely in Chamtal district of Afghanistan's northern Balkh province on Thursday, an army spokesman in the province Abdul Hadi Jamal said Friday.

The militants, according to the official, were planting a mine on a road in Yangi Qala area of Chamtal district Thursday evening to target the security forces convoy when it exploded prematurely, killing all the trio on the spot.

Taliban militants who are active in the restive district have not yet commented.