Police in the UK have issued an appeal after gas was released on London tube train.
British Transport Police said the gas is believed to have been CS gas – a type of tear gas.
A number of passengers were treated at the scene for coughing and lack of breath.
Police said there are no further concerns for their health.
Further info has shown the gas, believed to be CS spray, was used during a fight on the train. Efforts are ongoing to locate those involved.
Passengers on-board suffered coughing etc. They were treated and there are no further health concerns.
More info: https://t.co/3PbznR51Jr
— BTP London (@BTPLondon) July 20, 2019
Investigators said they believe the gas was used during a fight on the train – and have released images of a number of people they believe may be able to assist their investigation.
The incident happened shortly after 9am this morning.
Anyone who can identify the people in the pictures is urged to contact British Transport Police.