Armed gangs operating mostly in remote parts of northwest Nigeria have carried out violent attacks against villagers, schools and motorists, abducting hundreds for ransom.

The mass kidnapping is a first in the insurgency that spread to Burkina Faso from neighbouring Mali in 2015 despite costly international military efforts to contain it.

Ismail Sabri Yaakob says he is waiting for a report from the police and the National Security Council on the matter.

However, the mercenaries in this case were believed to have bungled the operation, nabbing the less prized of two men.

Cleo Smith disappeared from her family's tent in Western Australia in October, sparking a major search operation that many feared would end in tragedy.

The footage released on social media showed Wilson Joseph, wearing a suit and surrounded by armed men, in front of coffins containing the bodies of five members of his gang.

Talks are under way with kidnappers to seek the release of the missionaries abducted over the weekend outside the capital, Port-au-Prince, by a gang called 400 Mawozo.

The group was in Haiti to visit an orphanage when their bus was hijacked on Saturday outside the capital Port-au-Prince, amid a spike in kidnappings following the murder of President Jovenel Moise.

Kidnapping for ransom is increasingly common in the region but authorities say no ransom was paid in this case.

The interior ministry says investigators watched 700 hours of CCTV footage and searched 200 taxis.

Hospital reports say she was admitted with swellings and rope marks on her wrists and ankles.

Heavily-armed criminal gangs in northwest and central Nigeria have stepped up attacks in recent years, kidnapping for ransom, raping and pillaging.