Tunisia militants kill four police in checkpoint attack

TUNIS Around 20 al Qaeda-linked 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 fighters operating in mountains along the Algerian border, were behind Tuesday night's attack, interior ministry spokesman Mohamed Ali Aroui told reporters.

Tunisia recently completed its transition to democracy after the 2011 uprising against autocrat Zine El-Abidine Ben Ali, but security remains a key worry due to the emergence of hardline Islamist groups.

"Around 20 terrorists attacked a checkpoint and killed four police. They opened fire on the checkpoint and then they fled with the police weapons," the spokesman said.

Local radio reported a separate groups of militants had raided houses near Kef, also near the Algerian frontier, holding residents at gunpoint to steal food and supplies before fleeing into the mountains.

Tunisia is waging a campaign against Islamist militants, who mostly target security forces. Since April last year, thousands of soldiers have been deployed to drive out militants from the Chaambi range bordering Algeria.

Fighters took refuge in the Chaambi range after fleeing the French military intervention in Mali last year.

Last year, Okba Ibn Nafaa killed least 14 soldiers in attacks on two checkpoints, the deadliest strike on Tunisia's armed forces ever. The group's name refers to an early Muslim who led the Islamic conquest of the Maghreb.

(Reporting by Tarek Amara; Writing by Patrick Markey; Editing by Raissa Kasolowsky)