![Firefighters work on site where a large explosion occurred at a restaurant in Sapporo, Japan, Dec.16, 2018. According to local media reports, an explosion that triggered a fire occurred at a restaurant in Sapporo in the evening. The cause of the explosion is still unknown. At least 20 people have been reported injured and taken to hospitals. (Photo/Agencies)](http://www.ecns.cn/hd/2018/12/17/b3dbe6426439475ab1b540fad0c8aab7.jpg)
Firefighters work on site where a large explosion occurred at a restaurant in Sapporo, Japan, Dec.16, 2018. According to local media reports, an explosion that triggered a fire occurred at a restaurant in Sapporo in the evening. The cause of the explosion is still unknown. At least 20 people have been reported injured and taken to hospitals. (Photo/Agencies)
![Firefighters work on site where a large explosion occurred at a restaurant in Sapporo, Japan, Dec.16, 2018. According to local media reports, an explosion that triggered a fire occurred at a restaurant in Sapporo in the evening. The cause of the explosion is still unknown. At least 20 people have been reported injured and taken to hospitals. (Photo/Agencies)](http://www.ecns.cn/hd/2018/12/17/ded73062a6054389acb58924374d802f.jpg)
Firefighters work on site where a large explosion occurred at a restaurant in Sapporo, Japan, Dec.16, 2018. According to local media reports, an explosion that triggered a fire occurred at a restaurant in Sapporo in the evening. The cause of the explosion is still unknown. At least 20 people have been reported injured and taken to hospitals. (Photo/Agencies)
![Dozens of people were injured Sunday in an explosion at an izakaya, or a Japanese-styled pub, in the city of Sapporo in Japan\'s northernmost Hokkaido prefecture, Dec.16, 2018. (Photo/Agencies)](http://www.ecns.cn/hd/2018/12/17/8385df382bb44175bf0f61e15d608665.jpg)
Dozens of people were injured Sunday in an explosion at an izakaya, or a Japanese-styled pub, in the city of Sapporo in Japan's northernmost Hokkaido prefecture, Dec.16, 2018. (Photo/Agencies)
![Dozens of people were injured Sunday in an explosion at an izakaya, or a Japanese-styled pub, in the city of Sapporo in Japan\'s northernmost Hokkaido prefecture, Dec.16, 2018. (Photo/Agencies)](http://www.ecns.cn/hd/2018/12/17/cf567f8e0926415f958faa2492274245.jpg)
Dozens of people were injured Sunday in an explosion at an izakaya, or a Japanese-styled pub, in the city of Sapporo in Japan's northernmost Hokkaido prefecture, Dec.16, 2018. (Photo/Agencies)