Nine members of Tunisia's security forces were killed on Sunday in an attack in the west of the country close to the border with Algeria, state news agency TAP reported.
The television said a terrorist group had attacked a patrol of the National Guard-affiliated with the Interior Ministry in a mountainous area in the northwestern province of Jendouba.
The Interior Ministry confirmed the attack, but did not give an exact death toll.
Ministry spokesman Sofian al-Zaaq said a number of people were killed and injured in the attack, but without elaborating.
"The terrorist attackers threw a grenade at the first security car and there were confrontations with firearms," the report quoted al-Zaaq as saying.
No group has yet claimed responsibility for the attack.
Sunday's death toll is the highest since 2015 when militants carried out three major attacks, killing dozens, including security personnel.
In 2016, Daesh terrorist group staged deadly attacks on military and security posts in the eastern town of Ben Guerdane near Libyan border, killing 12 soldiers and seven civilians.