A riot has broken out at the central prison in Sierra Leone's capital, Freetown, with smoke billowing from the facility after the confirmation of a coronavirus case there.

Inmates at Pademba Road Prison had earlier on Wednesday set some buildings on fire in a protest that police and security forces were subsequently able to quell, Information Minister Mohamed Rahman Swaray told reporters.

"There are casualties but these are early days. When the dust settles we will be able to give you a more comprehensive account," Swaray said in a video streamed online.

Cecil Cole Showers, a spokesperson for Freetown's Pademba Road Prison, was quoted as saying by AFP news agency that a guard had been killed and dozens of inmates and guards were wounded.

A resident near the prison also told AFP that gunshots had been fired during the incident.

Security forces were later deployed around the prison and residents in the area were ordered to stay indoors.

The government had said on Monday that a recently arrived inmate had fallen ill with the coronavirus. The patient has been transferred out of the facility for treatment.

Sierra Leone has recorded 104 cases of the coronavirus, with four fatalities.

There are fears that the country is ill-equipped to handle a large outbreak because of its fragile healthcare system.

Pademba prison, which is designed to hold 324 inmates but now houses more than 1,000, was rocked by a series of riots in the 2000s due to overcrowding and poor conditions. Its numbers have risen in recent days with the transfer of inmates from a reintegration centre back to the prison, due to the pandemic.

Sierra Leone's prisons are chronically overcrowded and unsanitary, and local non-governmental organisations had earlier urged the government to release prisoners with minor convictions to ease the risk of infection.

In the statement on Monday, the government said that it was suspending criminal courts for a month to stem prison contamination.