The driver of a double-decker bus in London says the windows of the bus were blown-out today -- one of a series of incidents that has brought much of the city to a standstill.
Police say they're not treating it as a "major incident" on the level of the bus and subway attacks that killed more than 50 people two weeks ago.
But three subway stations and the bus have been evacuated, after
reports of smoke and the sound of explosions.
Police say one person was hurt.
A witness tells Sky TV that another subway passenger told him a backpack had exploded at a station.
Police in chemical protection suits have been seen preparing to enter the Warren Street station.
The company that operates the bus says the driver heard a bang and went upstairs -- where he found the windows blown out.
The company says the bus was otherwise intact, and that it had no reports of injuries.