A suicide bomber has killed at least three Chadian soldiers in an attack in the northern Malian city of Kidal.
Residents in Kidal said the bomber blew himself up next to a group of soldiers in a market.
Chadian and French troops have been in Kidal since February as part of efforts to fight Islamist militants who had taken power in the north of Mali.
Northern towns have been recaptured in the French-led operation but some fighters remain in desert hideouts.
Islamist groups took advantage of a coup in March 2012 to take control of the north of Mali, where they imposed a strict form of Islamic law.
This is the third suicide bombing in Kidal this year - and there have been other such attacks in Timbuktu and Gao.
The centre of Kidal is reported to be sealed off.
The city's deputy mayor, Abda Ag Kazina, blamed the attack on members of al-Qaeda's North African branch, the Associated Press news agency reports.
A Chadian military official told Reuters news agency four other soldiers were hurt in the attack.
Meanwhile, five Malian soldiers died when their helicopter crashed near the central town of Sevare, officials say.
An investigation into the crash is under way although an initial assessment blamed mechanical failure.
Earlier in the week, France began its withdrawal of troops from Mali - 4,000 soldiers were sent to the West African nation in January to help the weak Malian army recapture the north.
France said it acted when it did as the al-Qaeda-linked militants threatened to march on the capital, Bamako.
It hopes to have only 1,000 soldiers in Mali by the end of the year, handing over duties to an African force which currently numbers around 6,300 soldiers.
UN chief Ban Ki-moon has suggested that an 11,000-strong UN peacekeeping force, made up of African troops, be deployed in Mali.