Japan's southernmost prefecture, Okinawa, has declared a state of emergency over the Covid-19 pandemic, as the country grapples with a surge in infections six months before it is set to host the Summer Olympics, Reuters reported.

Okinawa Governor Denny Tamaki said emergency measures include asking restaurants and bars to close by 8pm and residents to refrain from non-urgent outings after 8pm.

The emergency is scheduled to last until February 7.