A "jihadist" militant detonated his explosives belt killing four policemen during a raid by security forces in southern Tunisia on Wednesday, the interior ministry said.

A "jihadist" militant detonated his explosives belt killing four policemen during a raid by security forces in southern Tunisia on Wednesday, the interior ministry said.

It said a firefight erupted between militants in the Tatouine governorate and a national guard unit acting on information from an "anti-terrorist" operation earlier the same day near Tunis.

"One terrorist element was shot dead while the other detonated his explosives belt, killing two officers and two agents of the national guard," it said.

Earlier, two suspected terrorists were killed on Wednesday during a security operation near the Tunisian capital, the interior ministry said.

Sixteen others, some of them armed, were arrested during the operation in the suburb of Ariana, it said in a statement.