About 150 people have suffered breathing problems after sulphuric acid spilled from a burst tank belonging to a chemical company in the western German city of Oberhausen and turned into a toxic cloud.

About 130 firefighters and emergency staff treated most people on the scene.

Five people had to be taken to hospital.

The spill was caused when a ship accidentally pumped hydrochloric acid into a tank containing sulphuric acid, causing the tank to burst, the German news agency dpa reported.

Firefighters' spokesman Joerg Preussner said that most people had only light breathing troubles, but that everyone in the area had been asked to stay inside and close the windows.

Train and bus lines were stopped for hours and city streets, a canal and a road were temporarily shut to keep people away from the area.

All schools and nurseries were ordered to keep children inside buildings until the early afternoon.

The visible cloud, which slowly moved to the north east of the city, was several hundred metres wide.

Mr Preussner said firefighters had used water cannons and successfully fought the cloud with water mist.

The burst tank was pumped empty and the toxic mixture was taken away by tanker trucks.