Ealing Broadway station had to have an emergency evacuation after a CS gas attack this Wednesday. Although there was no panic during the incident passengers experienced a burning sensation in their throat and lungs and had their eyes water before they managed to exit the station. Witnesses related how they saw hundreds of people emerging from the station coughing and spluttering.

The police will be viewing the station's CCTV footage but warn that given the large number of people who use the station it may be difficult to identify the culprits.

The canister which was released in the ticket area at the height of the rush hour - 6.30 in the evening - is not believed at this stage to be linked to terrorists. Police, fire and ambulance crews were dispatched and the station was given the all clear by 8pm.

No one is believed to be seriously harmed by the attack although one person suffered an asthma attack and was treated at the scene.