At least two people were killed in a building collapse in Paris Sunday following an explosion likely due to gas leak, according to media reports.The four-storey building in the eastern Paris suburb of Rosny-sous-Bois partially collapsed at 8 a.m., killing an eight-year-old child and an old woman, Xinhua reported citing news channel BFMTV.Ten people were injured, with four being in serious condition, and several others were still under the rubble, it added."It is an explosion likely caused by a gas leak. But, there is no certainty for the moment," Interior Minister Bernard Cazeneuve was quoted as saying.Some 150 firefighters were mobilised to rescue the building's occupants whose exact number was not immediately known.