Around 20 Islamist militants attacked a checkpoint in Tunisia's central Kasserine region, killing four police officers and stealing their weapons, the government said on Wednesday.
Okba Ibn Nafaa, a small brigade of al Qaeda-affiliated fighters operating in mountains along the Algerian border, were behind Tuesday night's attack, interior ministry spokesman Mohamed Ali Aroui told reporters.
"Around 20 terrorists attacked a checkpoint and killed four police. They opened fire on the checkpoint and then they fled with the police weapons," he said.
Tunisia is engaged in a campaign against Islamist militants who mostly attack security forces. Soldiers are also trying to flush out fighters from a base in the Chaambi mountains near Algeria.
Last year, Okba Ibn Nafaa killed least 14 soldiers in rifle and rocket-propelled grenades attack on two checkpoints, the deadliest strike on Tunisia's armed forces. The group's name refers to an ancient Islamist leader from the Maghreb.
Since April last year, thousands of soldiers have been deployed to flush out militants from the Chaambi range bordering Algeria, where some fled following France's military intervention in Mali last year.