A suspected militant was killed in clashes in southern Tunisia on Tuesday that also left two policemen wounded during a "huge" security sweep, the interior ministry said.

A suspected militant was killed in clashes in southern Tunisia on Tuesday that also left two policemen wounded during a "huge" security sweep, the interior ministry said.

"Since yesterday (Monday), specialist army units have been carrying out a huge security operation in the province of Kebili," the ministry said.

"At dawn today, during a successful raid and in an exchange of fire with a terrorist group, a terrorist was killed and eight others arrested."

The interior ministry said other gunmen had fled, and that two policemen were wounded by shots to their legs.

During the operation, the security forces seized grenades, a truck that was being fitted with a bomb, five cars, large sums of money, IT equipment and 30 mobile phones.

Tunisia has been rocked by violence since the mass uprising that toppled former strongman Zine El Abidine Ben Ali in January 2011, and has witnessed a surge in deadly attacks this year.

Since January, two opposition MPs have been killed, while some 30 policemen and soldiers have died in operations targeting terrorist groups believed to have ties to Al-Qaeda. 

Late last month, two botched suicide attacks at nearby coastal resorts heightened fears for the country's battered tourism sector.

The violence has fuelled a major political crisis in the birthplace of the Arab Spring, with the secular opposition accusing the ruling Islamist party Ennahda of failing to rein in extremist groups.