Nigeria, Africa’s top oil producer, announced a one-month lockdown to limit the spread of the coronavirus, banning all international flights and shutting land borders.

Authorities are advising residents of the commercial hub, Lagos, and the capital, Abuja, to stay indoors and avoid any “non-essential outings,” government secretary Boss Mustapha said in a statement. Lagos is one of Africa’s biggest cities, with about 20 million people.

The government has also suspended its weekly cabinet meetings as well as a meeting of state governors scheduled Thursday, Mustapha said. Court hearings are being suspended for two weeks from March 24, according to the judicial council in a separate statement. Nigeria has 36 confirmed cases of the virus.