ALGIERS, Algeria – Algerian army troops killed 21 armed Islamic extremists who were meeting Tuesday in a forest to plan attacks on the country’s capital, a ranking gendarmerie official said.

The official said that two others were captured in the assault on the group meeting in the Boukram forest in Boumerdes, some 20 kilometres (about 13 miles) from Algiers. A dozen Kalashnikovs, three rocket launchers and dozens of homemade bombs were recovered.

It was the deadliest assault on extremists in recent times in Algeria where al-Qaida in the Islamic Maghreb, or AQIM, carries out sporadic attacks east of Algiers.

The official, in the gendarmerie’s command post in Boumerdes, said intelligence sources had informed the army of the meeting. He spoke on condition of anonymity because he was not allowed to speak publicly about the operation.

The official described the dead as “terrorists,” the habitual reference for AQIM which operates in the region, sometimes striking at security forces in a drum of low-level violence.

The last major attack in Algeria was the attack on a desert oil plant in January 2013 that left 40 hostages, mainly foreigners, dead. It was claimed by a group headed by the feared Mokhtar Belmokhtar, loyal to al-Qaida but not to its Algeria branch.

AQIM struck in the Algerian capital in December 2007 in a double bombing that demolished U.N. offices, killing 17 U.N. staffers, and damaged the constitutional Council building across town.

There was no immediate official reaction to Tuesday’s army assault.