Nigeria's poor northeastern state of Borno, ravaged by a decade of attacks by the Boko Haram jihadist group, ordered a lockdown on Monday after a nurse with the medical charity Doctors Without Borders (MSF) died from the novel coronavirus.

It was the first coronavirus fatality in Borno, where there are fears that the disease could spread rapidly among the among the two million people displaced by the Boko Haram insurgency living in the Lake Chad region in overcrowded camps with poor sanitary facilities.

"I am hereby directing a lockdown that will require cessation of all movements in Borno State for an initial period of 14 days with effect from 10:30 pm (2130 GMT) on Wednesday... All citizens in Borno State are to stay in their homes," governor Babagana Umara Zulum said.

Several Nigerian states have already adopted strict confinement measures despite protests in a country where nearly half of the nearly 200 million population live in grinding poverty despite its oil wealth.

MSF said it would cooperate in identifying the people that the dead nurse came in contact with.

It also said it had stepped up sanitary measures to protect both its workers and patients.

The United Nations announced a second COVID-19 testing centre would be set up in the Borno capital Maiduguri, the birthplace of Boko Haram.

Only half of the roughly 700 health facilities in Borno state are still working and many have been damaged by the fighting.

The nurse was the 21st person to have died of coronavirus in Nigeria, according to official statistics, although experts say this is the tip of the iceberg. There have been 627 confirmed infections so far.