Islamist militants disguised as security officials killed three Tunisian policemen and a civilian in an attack near the border with Algeria, the state news agency TAP said on Sunday.

The agency did not name any group in the attack. Tunisia’s security forces have been battling militants from the banned Islamist movement Ansar al-Sharia, whose leader has declared allegiance to al Qaeda’s North Africa wing.

TAP said four gunmen dressed as Tunisian security officials killed the four and wounded two police and a border agent just after midnight in d’Awled Manna, in northwest Jendouba province.