Kenya's President Uhuru Kenyatta has said dozens of people who were filmed escaping from mandatory quarantine in the capital, Nairobi, will be arrested and returned to finish their isolation period.

The president spoke on Wednesday morning, just hours after the video was shared online. It showed some people jumping over a perimeter wall at one of the quarantine centres.

Local media reports placed the number of those who escaped at 50 but the government has not confirmed the figure.

President Kenyatta said the government knows the identities of all those who escaped and would arrest and take them back to the quarantine centre.

The ministry of health had on Tuesday evening said that police were investigating the escape.

Kenya's Citizen TV station said the break out took place during early dinner when it started raining and guards took cover from the rain.

More than 400 people are under forced quarantine for flouting curfew orders and drinking despite the closure of bars.

Some of those who arrived in the country before the ban on international flights came into effect have had their quarantine period extended after the ministry said that some isolation centres had not ensured social distancing.

Those in the centres have decried their poor hygiene conditions, saying they were likely to contract the virus there.