Tunisian security forces killed six "terrorists" overnight near Ben Guerdane after a deadly terrorist attack on the town near the border with Libya.

Tunisian security forces killed six "terrorists" overnight near Ben Guerdane after a deadly terrorist attack on the town near the border with Libya, the interior ministry said on Wednesday.

"Security and army units tonight eliminated five terrorists in the Benniri sector" near the frontier, the ministry said late Tuesday.

Early Wednesday it revised the toll, saying that a sixth suspect terrorist had been killed overnight.

Four Kalashnikov assault rifles were recovered, it added.

Tunisian media reports late Tuesday said security forces had surrounded a house where suspected militants were holed up, but this information has yet to be officially confirmed.

Benniri is a few kilometers (miles) south of Ben Guerdane which is still under curfew after Monday's dawn attack in which 36 assailants, 12 members of the security forces and seven civilians were killed.

The authorities said the attack was an unprecedented assault by the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group aimed at setting up a new stronghold in the country across the border from Libya.

Witnesses reported a massive security presence on Wednesday in Ben Guerdane, a town of 60,000 people.

The authorities have warned that mopping up operations after Monday's attack would continue.

Prime Minister Habib Essid said on Tuesday that about 50 extremists were believed to have taken part in the assaults on an army barracks and police and National Guard posts.

Defense ministry spokesman Belhassen Oueslati said 17 suspects were arrested on Tuesday near a military barracks and handed over to the National Guard for questioning.