Four people including two civilians were killed and two others injured as a remote- controlled bomb hit Imam Sahib district in Afghanistan's northern Kunduz province on Thursday, district governor Amanudin Qarishi said.

"A mine planted by militants on a road in Arbab Khalil village of Imam Sahib district was detonated by remote control when a team of police patrol was passing the area, killing four people including two police and two civilians," Qarishi told Xinhua.

Two more police constables sustained injuries in the blast, the official added.

However, the official without giving more details said that an investigation has been initiated into the case to identify and bring to justice those behind the bloody incident.

Kunduz has been the scene of increasing militancy over the past couple of years.

Taliban militants fighting the government to regain power are in control of Imam Sahib's neighboring district of Dasht-e-Archi over the past couple of months, and have been operating to expand their hold in the province.