Afghan officials have blamed the Taliban for attacking their security checkpoints in northern Sari Pul province, leaving at least seven members of their forces dead.
The insurgents also abducted two members of the force and left five wounded, officials said, adding that four Taliban fighters were killed in the gun battle.
The troops were in charge of providing security for fuel wells in the area.
The Taliban is yet to claim responsibility for Sunday's attacks.

US military marks 11th successive night of attacks on Iran
Trump says US airlines can now fly to Lebanon for first time since 1985
Bahrain, Kuwait, Jordan face renewed Iranian attacks after US hits Iran's south
Lebanese army enters southern town after Israeli withdrawal, in first test of US-brokered deal
Kuwait lodges formal protest with Iran over tanker attack; ministry says power station fires contained
