Five Chinese were presumably killed early Monday after an oil refinery blast rocked a settlement in the Zabaikalsky Kray in eastern Russia, news agencies reported.

The executive director of Zabaikalsky Refining Company, Arkady Chuprov, and a total of 18 Chinese were working at the oil refinery in the village of Dauria at around 4:25 a.m. local time (1925 GMT Sunday), when an explosion occurred inside the pumping station.

"The location of five of them, who happened to be in the blast center, has not been spotted yet, all of them are presumably killed," said a source in the regional prosecutor's office.

The blast then caused a fire in a main warehouse with about 2,000 tons of fuel oil.

At around 12:40 local time (0340 GMT), some 30 meters from a burning oil fuel tank, a body was found, whose identity and cause of death were currently being established, a spokesman for regional emergencies department was quoted by the RIA Novosti news agency as saying.

The explosion was probably caused by the use of open fire indoors. Huge flames were seen after the blast, whose waves shattered the windows in the adjacent four residential houses some 300-500 meters away.

No casualties were reported in the Dauria village. Residents have been evacuated to a safe place in case of more blasts.

Firefighters and repair workers were working at the scene to put down the fire and clean up the aftermath of the explosion.

The regional prosecutor's office has launched an investigation into the incident.