A terrorist attack has occurred at a gas-refining plant in the Russian republic of Ingushetia, which borders Chechnya, the RIA-Novosti news agency reports quoting the republic's Interior Ministry. The blast happened in the village of Vosnesenovskaya at 2:30 a.m. Moscow time on Tuesday. "Criminals planted two powerful shaped charges that went off practically simultaneously," a source in the ministry said.After the blast oil began leaking and caught fire, the flame was 15-20 m. high, he added. It took fire-fighters approximately three hours to put out the fire. The oil leak has been stopped and the fire put out to date. No casualties have been reported. The Interior Ministry said that a terrorist attack was the main cause of the incident. A criminal case was opened, an investigation is in progress.