The Salafist Group for Preaching and Combat says the move is proof of ‘sincerity’.
In Sunday’s attack, fighters are said to have fired a grenade on a police vehicle at a highway crossroads as officers were changing shifts, Liberte reported.
A second police vehicle came under machine-gun fire, Liberte reported, citing witness accounts.
Security forces dispatched reinforcements, prompting a two-hour fire fight.
It was not immediately clear whether any of the assailants were detained or injured.
There was no independent verification of the attack.