MOSCOW, December 28. /TASS/. A total of 13 people have been injured in an explosion in a supermarket in St. Petersburg, according to the latest data, eight of them remain in hospitals, the city’s Vice-Governor in charge of social issues Anna Mityanina reported on Thursday.

Earlier reports said the blast had left ten people injured.

"As of 08:00 (on December 28, 2017), the total number of people injured in the blast in a supermarket in Kondratyevsky Avenue is 13. Of these, five refused to be taken to hospital. Five of those remaining in hospitals are in a moderately grave condition, while three are in a satisfactory condition" she wrote on Twitter.

There are no children among those injured, the press service of the city’s healthcare committee said.

An explosion at a supermarket in St. Petersburg’s Kondratyevsky Avenue was reported at about 18.30 Moscow Time on Wednesday. According to preliminary reports, an unidentified explosive device was detonated in the Gigant-Hall entertainment center on the first floor near self-storage lockers of the Perekrestok supermarket.