Algeria announced on Sunday the arrest of three suspected Islamists who confessed to planting a home-made bomb that reportedly killed two soldiers patrolling near the border with Tunisia.
"Members of the National Guard arrested three backers of terrorist groups on June 3 at Tebessa," about 550 kilometres (340 miles) southeast of Algiers, the defence ministry said.
"They admitted to having planted the home-made bomb which exploded as a military patrol passed by" near Bir el-Ater, about 100 kilometres south of Tebessa and some 15 kilometres from the border.
It is the first official confirmation of the attack, which occurred at dawn on Saturday, but the ministry did not say if there were any casualties.
Security sources told AFP on Saturday that the blast killed two soldiers and wounded four.
Algerians had hoped that a 2005 peace and reconciliation charter would turn the page on a 1991-2002 civil war that cost 200,000 lives.
But Islamist groups remain active in the south and east, largely targeting security forces.