The assailants, suspected of being affiliated with the armed Ansar-ud Din insurgent group – an ally of al-Qaeda in the Islamic Maghreb – attacked the town of Talahandaq late on Thursday.
The group released a statement saying the area had been hit by rocket attacks.
This latest incident comes two days after 10 extremists were killed by French forces in northern Mali.
After a French intervention in Mali in 2013, terrorist groups have been repositioning themselves in the north.
Despite the presence of French and UN peacekeeping forces, insurgents remain very active.