Japanese carriers are offering users a function to register and check whether a person is safe.

Three major mobile phone carriers -- NTT Docomo, KDDI and Softbank -- are now operating the disaster message board.

Japan's health ministry says about 2,000 people who have tested positive for the coronavirus have been isolating at home.

A ministry survey shows that of the 8,711 people who had tested positive by April 28, 1,984 were recuperating at home.