At least four people were killed and 30 others injured when two trains collided in the Moscow region, the Emergencies Ministry said Tuesday. According to the Moscow regional department of the ministry, several carriages of a cargo train derailed and hit a passenger train going at the neighboring track to Moldovan capital Chisinau from Moscow. "Preliminary investigation showed the crash happened due to the cargo train's broken bogey," the Interfax news agency quoted an unnamed source in the Russian Railways company as saying. The number of casualties might grow as rescuers removed passengers form the wrecks. The collision happened near the Bekasovo station about 70 km southwest of Moscow.