Yemen has reported its first two deaths from the novel coronavirus, its health minister told Yemen TV late on Wednesday.

Yemeni authorities also reported multiple coronavirus infections, five, for the first time on Wednesday, after the United Nations said it feared the disease could be spreading undetected in a country where millions face famine and lack medical care.

The new cases were reported in the southern Yemeni port city of Aden, forcing authorities to impose a three-day, 24-hour curfew.

Previously, Yemen had detected only a single case. International health officials have long warned that Yemen’s population could be extremely vulnerable to an outbreak, which would be difficult to detect in a country where health infrastructure has been degraded by poverty and war.

On Tuesday the United Nations said there was a “very real probability” the virus was circulating within communities.