Tunisian security forces pressed a search for terrorists near the Libyan border on Tuesday after a deadly raid the authorities described as an "unprecedented" assault by the Takfiri group ISIL.

Tunisian security forces pressed a search for terrorists near the Libyan border on Tuesday after a deadly raid the authorities described as an "unprecedented" assault by the Takfiri group ISIL (so-called Islamic State in Iraq and Levant).

Prime Minister Habib Essid said around 50 extremists were believed to have taken part in Monday's coordinated attack on an army barracks and police and National Guard posts in the border town of Ben Guerdane.

He said that 36 attackers had been killed and seven captured in a fierce battle that also saw the deaths of seven civilians and 12 security force personnel.

Essid told a news conference that the militants "murdered one internal security force member in his own home".

He said three civilians and 14 security personnel were also wounded.

Interior ministry spokesman Yasser Mesbah said the search for any militants still at large was continuing in the border area.

He said a nighttime curfew imposed in the town after the attack had been well respected and that the situation was "stable".

On Monday, Essid said that the operation's aim had been to create a "Daesh (ISIL) emirate" in Ben Guerdane.

President Beji Caid Essebsi said the "unprecedented" Takfiri attack was "maybe aimed at controlling" the border region and vowed to "exterminate these rats".
Residents told AFP the assailants appeared to be natives of the region.

They stopped people, checked their ID cards apparently to seek out members of the security forces, and announced their brief takeover of Ben Guerdane as "liberators".

It was the second deadly clash in the border area in less than a week as Tunisia battles to prevent the large number of its citizens who have joined ISIL in Libya from returning to carry out attacks at home.