Six other policemen were wounded in the fighting at security checkpoints in Balkh's Nahri Shahi district, local officials said.
There were also casualties among Taliban members, they added.
Afghanistan has seen a surge in violence as peace talks that started in September between the Taliban and the Afghan government have so far failed to achieve a breakthrough.
The majority of bomb attacks in Kabul in recent months have been sticky bombs, which are explosive devices with magnets attached to vehicles and detonated by remote control or timer.
Since 2001 when the United States invaded Afghanistan, over 100,000 people have been killed in the war, including more than 4,000 ISAF soldiers and civilian contractors, more than 62,000 Afghan national security forces, 31,000 civilians, and even more Taliban members. (ILKHA)