Al-Qaeda in the Islamic Maghreb on Saturday said they carried out Friday's attack on a UN military camp in Timbuktu in Mali's restive north.
At least four suspected militants and a Malian soldier were killed in the attack which the group said was designed to send "a clear message" of its intention and capacity to target the UN's peacekeeping MINUSMA mission.
The group said in a statement that three fighters from the al-Quds Brigade of its Sahara division stormed the former hotel serving as the mission base, one detonating a vehicle-borne improvised explosive device at the entrance and the two others entering inside.
The attack came three months after a similar strike on the Radisson Blu Hotel in Bamako and one month after a raid on a top hotel in Burkina Faso.
The militant group has vowed to continue with a "series of operations to cleanse the land of Islam and Muslims from the dens of the Crusader occupiers and their mercenaries".
A Malian police source indicated two suspects, who army sources said had been arrested in the aftermath of the attack, were Saturday released.
"The people arrested Friday on suspicion of being terrorists or their accomplices have been freed for lack of evidence," the Timbuktu gendarmerie source told AFP without giving further details.
Defence Minister Tieman Hubert Coulibaly had Friday spoken of "half a dozen" fighters carrying out the attack, with three gunned down and one blowing himself up.
Three Malian soldiers were also wounded.
The assault came just a day after the fabled city celebrated the restoration of its greatest treasures -- earthen mausoleums dating to mediaeval times and destroyed during an Islamist takeover in 2012.
In a statement via Mauritanian news agency Al-Akhbar, Al-Qaeda in the Islamic Maghreb said three fighters whose nationalities were not immediately clear carried out the raid and were all killed.
The group added that "several soldiers" had also died with others injured.
Army sources reported the situation Saturday afternoon as calm in Timbuktu as Coulibaly attended the funeral of the slain soldier, named as commander Karim Niang. The sources added they had carried out patrols through the night across the city.
Sources close to Coulibaly meanwhile said he would be meeting with city officials to discuss boosting security.
Northern Mali fell under the control of Tuareg-led rebels and jihadist groups linked to Al-Qaeda in 2012.
The Islamists sidelined the Tuareg to take sole control. Although largely ousted by a French-led military operation in January 2013 the militant groups remain active.