MOSCOW, August 9. /TASS/. About 20 apartment buildings and four social facilities have sustained damage in an explosion at the Zagorsk Optical-Mechanical Plant in the town of Sergiyev Posad near Moscow, according to the Telegram channel of the local municipal administration.

"As a result of the blast, <...> four social facilities have been damaged: the Luch sports facility, Schools No. 19 and 21, Sergiyev Posad College and about 20 apartment buildings," its statement said.