Militants attacked a Malian army post near the border of Burkina Faso on Sunday, killing 11 soldiers, a Mali defence ministry spokesman told Reuters.
It was not immediately clear who was responsible for the attack, but Islamist groups including al Qaeda affiliates have been resurgent in recent months in Mali, attacking army positions beyond their usual strongholds in the north.
"The post was attacked between 4 a.m. and 5 a.m. in Boulkessi, and there were 11 killed and five wounded," said defence spokesman Colonel Abdoulaye Sidibé.
He said a deployment of troops had been sent to the town as reinforcements, but did not say if the attackers had been caught by Sunday night.
Armed groups block Mali interim government installation in Timbuktu
Meanwhile, armed groups took over parts of Timbuktu on Monday to prevent Malian interim authorities from being installed there under a peace pact meant to end years of lawlessness, the defence ministry said.
The return of state authority to northern Mali was supposed to fill a vacuum that has rendered it a launch pad for regional jihadi attacks across the region.
Islamist groups such as Ansar Dine have stepped up their insurgency in Mali over the past year. In 2016, they carried out dozens of attacks on United Nations and other targets and spread south into areas previously deemed safe.
Al Qaeda's North African ally al Mourabitoun in January claimed responsibility for a suicide bomb attack on a military camp in northern Mali that killed up to 60 people and wounded more than 100 others, an attack it said was revenge against groups cooperating with French forces in the region.
France intervened in Mali in 2013 to drive back Islamist groups that seized the desert north a year earlier and maintains a regional operation aimed at stamping out insurgents.