Five people, all believed to be Chinese, have been killed in an explosion at an oil refinery in Siberia. Russian news agencies said today that the explosion took place overnight at a refinery in the village of Dauriya in the Zabaikalsky region of southern Siberia. The ITAR-TASS and RIA-Novosti news agencies reported that 18 people were present in the refinery at the time of the blast, all of them believed to be Chinese.