Japan's health ministry has reported that 130 cases of coronavirus clusters and other multiple infections were confirmed across the nation in the week to November 9.
The number rose by 27 from the previous week, an increase of 26 percent. Ministry officials are on high alert.
The ministry is compiling numbers of infection clusters confirmed by local governments nationwide, along with other group infections involving two or more people.
The largest number, 28 cases, involved restaurants and other eating places. It was followed by 27 at welfare facilities, including nursing homes for the elderly.
Businesses and government offices saw 22 instances, followed by 17 at medical institutions and 16 at schools and other educational facilities.
The ministry has been sending teams of anti-cluster experts to areas with sharp rises in infections to support local governments' efforts to contain the spread of the virus.