A gas explosion in an apartment building in Russia’s Far East killed at least nine people on Saturday, including four children, according local authorities. A section of the five-story building in the town of Tymovskoye on Sakhalin island collapsed after a gas cylinder exploded in one of the apartments at around 5:30 am Moscow time, authorities said. Rescue teams were searching for more victims under the rubble, Sakhalin Governor Valery Limarenko wrote on Telegram. Some of the 33 people known to have lived in the building remained unaccounted for, he said. Sakhalin is located in the Pacific Oc…