Watch: Up to 20 people injured as cranes collapse on rows of buildings
Up to 20 people are believed to have been injured after two cranes being used in the restoration of a bridge in the Netherlands fell on to a row of buildings.
Ton Koot, a spokesman for the local fire brigade in Alphen aan den Rijn, told national broadcaster NOS that heavy machinery is being moved to the scene in case people are trapped under rubble and need to be rescued.
Mr Koot said he does not know how seriously injured the victims are.
Amateur video shown on NOS shows the cranes on a pontoon carrying a large section of the bridge when they began to shift and topple over on to the houses.
Witness Dick van Smirren, who filmed the incident, told NOS that he saw the bridge deck being carried by the cranes start to move, then it swung and pulled the cranes with it on to the houses.
"You see the cloud of dust rise - that is a terrible image and you think, 'Who is under there?' You can't believe what you see," he said.
Local authorities urged people to stay away from the scene to allow rescuers to carry out their work. Rescuers with sniffer dogs are on their way to the scene to check for survivors.
The Dutch Safety Board, which investigates serious accidents, is sending a team to the scene.