The official APS news agency quoted paramilitary police as saying an armed group ambushed the gendarmes on Thursday while they were on patrol, 45 km west of the port city of Bejaia.
It gave no further details.
Attacks blamed on Islamist opposition fighters have now claimed at least 13 lives this week, including two soldiers.
Algeria plunged into a spiral of violence after the army cancelled parliamentary elections in 1992 that a now-banned Islamic party was poised to win.
Human rights groups estimate more than 150,000 people died, mostly at the hands of fighters who took up arms to overthrow the government and create an Islamic state.
Violence has sharply fallen in the last two years bringing back some foreign investment.
But security analysts expect the remaining active groups still operational in the North African country to intensify their attacks to try to disrupt the presidential election process ahead of voting on 8 April.