Stronger measures to prevent the spread of the coronavirus officially started Monday in Osaka, Hyogo and Miyagi prefectures as part of efforts to stem a sharp resurgence in infections in the three areas.

The steps, effective for one month until May 5, include fines for restaurants that ignore orders to shorten operating hours and requirements for customers to wear masks when patronizing such establishments.

The three prefectures are the first to be designated as being on the brink of a state of emergency under a revised law that took effect in February. Specifically, the city of Osaka and nearby Kobe, Ashiya, Nishinomiya and Amagasaki, as well as Sendai, will be subject to the stronger measures.