France announced it was expanding its operation against Islamists to the wider Sahel region last month
Two UN peacekeepers have been killed and seven others were injured in a suicide attack on a UN patrol base in northern Mali.
A pick-up truck laden with explosives drove into the UN camp in Ber, 50km (30 miles) east of Timbuktu, on Saturday.
A suicide attacker was among the dead, which included two soldiers from Burkina Faso serving with the UN.
It is not yet clear who was behind the attack, which has been condemned by UN Secretary-General Ban Ki-moon.
France intervened militarily in Mali last year in a bid to drive out Islamists who had taken advantage of an uprising by Tuareg rebels in the north of the country.
‘No checkpoint’
The attack took place at 11:30 GMT, the UN Multidimensional Stabilisation Mission in Mali (Minusma) said.
One eyewitness, who saw the aftermath of the blast, said Burkinabe troops had set up camp in Ber after the town was taken over by rebels last month.
“There was no checkpoint. The bomber was able to drive the vehicle right into the camp, among the tents, before blowing himself up,” he added.
Tuareg separatists are fighting for the independence of northern Mali
Two peacekeepers, who were also from Burkina Faso, were seriously injured in the attack.
It comes after three other international peacekeepers – two Bangladeshi, one Chadian – were injured when their vehicles drove over mines in two separate incidents at the end of last week.
Acting director of Minusma David Gressly said his force was “paying too heavy a price in Mali given that the peacekeepers are here precisely to ensure a return to peace and stability”.
Militants belonging to al-Qaeda in the Islamic Maghreb are known to use similar tactics such as the ones used in Saturday’s attack, says the BBC’s Alex Duval Smith in Mali.
Peace talks aimed at drawing up a road map for peace between the Malian government and Tuareg separatist rebels are due to resume in September.
It comes after three weeks of talks in July and August, which were mediated by the Algerian government.
But these talks do not include al-Qaeda or other Islamist elements involved in the conflict, our reporter says.
One of the separatist groups involved in talks, the National Movement for the Liberation of Azawad (MNLA), issued a statement on Saturday condemning the Ber attack and offering its condolences to the people and government of Burkina Faso.