Three female suicide bombers have attacked a refugee camp in north-eastern Nigeria, killing at least 27 people.

Dozens more were injured after the women blew themselves up outside the camp near Maiduguri in Borno state.

The attack bore the hallmarks of Boko Haram in an area known to be a militant stronghold. The north-eastern city is at the heart of a fight between government and jihadist forces who have waged an eight year insurgency to create an Islamic state in northern Nigeria.

Officials said 83 people were wounded in the blast, according to Reuters, in an attack that will shake the army's renewed control of the area.

Nigeria's military won back large swathes of territory from the militants but in the last few weeks they have struck back with at least 143 people being killed since June.

Boko Haram's better-known faction, led by Abubakar Shekau, has mainly based itself in the sprawling Sambisa forest, and been characterised by its use of women and children as suicide bombers targeting mosques and markets.

A rival faction - based in the Lake Chad region, led by Abu Musab al-Barnawi and boasting ties to Islamic State - has in the meantime quietly become a deadly force capable of carrying out highly-organised attacks.

Last month, an oil prospecting team was captured by al-Barnawi's group. At least 37 people, including members of the team, died when rescuers from the military and vigilantes attempted to free them.

The Boko Haram insurgency has killed 20,000 people and forced some 2.7 million to flee their homes in the last eight years.

Additional reporting by Reuters.