A bomb blast has ripped through an oil storage depot in the town of Neftekumsk in Russia's Stavropol region.
The explosion occurred in the early hours of Saturday morning, according to news reports. There were no reported injuries.
The blast, which according to preliminary information was due to an explosive device planted underneath a 5,000-tonne oil cistern, occurred at 03:00 Moscow time (23:00 GMT on Friday), emergency officials said as quoted by the ITAR-TASS news agency.
Another explosive device was reportedly found under another cistern, and the police were trying to disarm it, sources quoted by RIA-Novosti said.
There were no casualties, officials said.
Stavropol region borders the volatile Caucasus, including the war-torn republic of Chechnya.