The attack took place at around 1:00 p.m. local time (0800 GMT) when the convoy heading to conduct an operation against illegal mining activities was ambushed by militants, the sources told Xinhua on condition of anonymity.
The militants, positioned on nearby hilltops, opened fire on the police personnel as they passed through the area, the sources said.
The attackers also set five police vehicles on fire, while an intense exchange of fire continued in the area following the attack.
A heavy police contingent was called in, and additional personnel were dispatched to the area as security was placed on high alert, according to the sources.
Identities of the attackers were not revealed by the sources.