Officials Russia's Rostov region have opened a criminal investigation hours after a gas explosion at an apartment building killed an adult and a child.
The explosion on May 12 in the Kamensky district of Rostov damaged several apartments in the building, which is at risk of collapsing, district officials said.
Two other people were seriously injured and were taken to the hospital, they added.
The TASS news agency reported that investigators have seized documents relevant to the case from the gas company that provides service to the area.
In January, five people were killed in the Rostov region when a natural-gas explosion partially destroyed a residential building in the town of Shakhty.