Four Tunisian police officers were killed during a militant attack in the central region of Kasserine, the government said.
"On 18 February, following a terrorist attack in Boulaaba in the governorate of Kasserine, four heroes of the National Guard were martyred," the interior ministry stated, without giving further details.
Boulaaba is part of a mountain range on the Algerian border, which is home to Tunisia's main jihadist group, al-Qaeda-linked Phalange Okba Ibn Nafaa.
The terrorist attack happened at a time when the Tunisian troops had been put on alert along the Libyan border due to the murder of Egyptian Christians in Libya by ISIL militants. On Sunday night, ISIL posted a video on the Internet showing the execution of 21 Egyptian Christians.
The jihadist group is accused of having launched a series of attacks on the Tunisian army and politicians over the past two years. The Islamist fighters are blamed for a July 2014 attack which resulted in the death of 15 Tunisian soldiers. Dozens of soldiers and police officers have been killed or wounded by Islamist militants in ambushes. Tunisia's army has implemented ground and air campaigns against the group since 2012 without success.