Two Chadian soldiers are dead after suspected militants attacked their position in northern Mali.
Security officials say suicide bombers detonated a car filled with explosives on Wednesday in the city of Tessalit.
There was no immediate claim of responsibility. However, al-Qaida-linked militants have continued to launch sporadic attacks in the region since being scattered by a French-led offensive earlier this year.
The Chadian soldiers were part of a U.N. peacekeeping mission that is taking over security responsibilities.
Local officials say at least one civilian was killed in the attack.
Mali has seen a surge in violence in recent weeks.
Earlier this month, President Ibrahim Boubacar Keita cut short a trip to France to deal with a mutiny at a military camp near Bamako and clashes between Malian soldiers and MNLA rebels in Kidal.
Last month, a suicide bombing in the northern city of Timbuktu killed at least four people. Al-Qaida in the Islamic Maghreb claimed responsibility.
Keita's government has been trying to restore order after 21 months of turmoil that included a Tuareg uprising, a coup in Bamako and an Islamist militant takeover in the country's north.