Arrest after CS gas released on Tube at Oxford Circus
A man has been arrested after CS gas was released during a fight on a London Underground train.
It happened at 09:13 BST onboard a Victoria line Tube train at Oxford Circus on Saturday.
British Transport Police (BTP) said a number of people were treated at the scene by paramedics for coughing and shortness of breath.
The 24-year-old was arrested on suspicion of affray and administering poison with intent to injure or annoy.
He has been released under investigation "while officers carry out further inquiries", BTP said.
BTP, which launched a manhunt for two men after a "fight broke out between a group of people", still urged any witnesses to come forward.
Anyone who witnessed it, or who knows the identity of the suspects, is asked to contact the force.
CS gas, also known as tear gas, can cause a burning sensation around the eyes and difficulty in breathing.