Mechanical failures caused a BoltBus to burst into flames on the Massachusetts Turnpike near Newton on Monday afternoon.

The fire started in the engine and gas buildup caused an explosion that blew out the bus windows, State Police spokesman Dave Procopio told The Boston Globe.

The driver and the 47 passengers evacuated the bus moments before the flames consumed the interior of the bus.

Procopio said that no passengers were carrying anything explosive or hazardous that may have contributed to the explosion and that the driver and passengers exited the bus minutes before the fire started. No one was injured in the blast.

The bus left New York at 11 a.m. bound for Boston. The bus made an unscheduled stop in Connecticut around 3 p.m. for maintenance. Two hours later, the bus began overheating and drivers signaled to the driver, screaming, “You’re on fire!”

Ashley Sears, a spokesperson for Greyhound Lines, Inc., which owns the Bolt line, said, “Once the driver noticed smoke, the driver pulled over, evacuated the bus and called local authorities." The driver is not facing any charges at this time.

Two other busses arrived about an hour later to pick up the rattled but unharmed passengers and bring them to South Station.

The Federal Motor Carrier Safety Administration will determine if the bus was in violation of any motor carrier laws.