BREAKING NEWS: At least four people killed by a bus in Moscow

At least four people killed by a bus in Moscow



At least four people are said to have died after a bus came off the road and hurtled down a set of stairs leading to a metro station.



Horrifying video footage from the scene posted on social media showed a bus veering off the road and plunging down the steps of a pedestrian underpass, crushing several people beneath its wheels.



It happened on Kutuzovsky Avenue, near the Slavyansky Bulvar metro station in Moscow.



Reports vary from four to five people being killed and between 10 and 15 have been injured.



The reason as to why or how the bus - used for public transport - came off the road is still being investigated by detectives.



Police believe there are two possible causes, according to RIA Novosti.



Either the vehicle's brakes failed or a car cut ahead of the bus, causing it to veer off its intended path.



Another angle shows the bus seemingly stationary on the side of a snowy road before it appears to pull away in the direction of the metro station.



Terrorism is not being considered, it is understood, but the driver was detained by police. 



The incident occurred on one of the Russian capital's busiest roads near the Slavyansky Boulevard metro station.



Monday was an ordinary working day in Russia where Orthodox Christmas will be celebrated on January 7.



An unnamed emergency services source told the TASS news agency that the number of fatalities had risen to five people.



There were also unconfirmed reports that some 15 people had been injured.



The Interfax news agency said investigators were looking into whether the incident had occurred as a result of a technical fault with the bus.



Ten ambulances, fire service personnel, and three medivac helicopters were on the scene, agencies reported.



Mayor of the capital, Sergei Sobyanin, took to Twitter to express his condolences to the families and friends of the victim.