Japanese Prime Minister Yoshihide Suga declared a state of emergency over the Covid-19 pandemic on Thursday for Tokyo and its surrounding region amid a surge in infections, dpa news said. The declaration covers the capital and its three neighbouring prefectures – Chiba, Kanagawa and Saitama – considered at highest risk of infection with the coronavirus, Suga told a meeting of the government’s pandemic response team. Speaking at a news conference, Suga urged residents in the four prefectures to refrain from non-essential and non-urgent outings after 8 pm (1100 GMT). About half of recent nationwide infections were from the four prefectures, the premier said. He added the measure takes effect on Friday and lasts until February 7 and vowed to improve situations in the month. However, Hiroshi Nishiura, a professor at Kyoto University Graduate School of Medicine, told an expert panel advising the government on Wednesday that it would take two months or so for the number of new daily infections in Tokyo to fall below 100. The move comes as Japan reported 7,490 new infections on Thursday, marking the highest daily tally for the third day in a row, according to broadcaster NHK. And all of the four prefectures posted their record numbers of daily cases, including 2,447 in Tokyo. The number of patients with severe symptoms in the capital has grown to a record 121, NHK reported. Tokyo has confronted a "serious crisis," Governor Yuriko Koike told a news conference. The governors, including Koike, of the four prefectures decided earlier this week to request that bars and restaurants shorten business hours from Friday in order to curb new infections.