The troops were patrolling on foot near Aguelhok, which is close to the border with Algeria, when they were attacked.
The troops were patrolling on foot near Aguelhok, which is close to the border with Algeria, when they were attacked, according to a statement from the multinational UN force, MINUSMA.
A military source told AFP that the soldiers belonged to Chad's contingent.
Stationed in Mali since July 2013, MINUSMA has just over 12,000 military and police personnel working on what is considered the UN's most dangerous active peacekeeping deployment.
The attack was the latest in "a wave of violence in the last weeks," MINUSMA chief Mahamat Saleh Annadif was quoted in the statement as saying.
A UN peacekeeper from Liberia was killed and nine others injured early this month in a rocket and mortar attack near Timbuktu.
The attack, like many others in the last weeks, was claimed by a powerful jihadist alliance, the Group to Support Islam and Muslims (GSIM), a fusion of three Malian jihadist groups with previous Al-Qaeda links.
It is headed by Malian jihadist Iyad Ag Ghaly, a former leader of the Islamist group Ansar Dine.
Mali's north came under attack from jihadist groups linked to Al-Qaeda in 2012 who hijacked an ethnic Tuareg-led rebel uprising.
Though the Islamists were largely ousted by a French-led military operation in January 2013, jihadist groups continue to mount attacks on civilians and security forces in the arid remote north.