Armed police stormed a train after a railway worker was stabbed at London Euston Station.

Police carrying guns boarded a train as it sat at the platform in just after 7am this morning (Thursday).

The incident caused major disruption and services from Watford Junction were affected during the rush hour.

A woman on a train on the next platform wrote on social media: "Well, this is dramatic. Train being held at Euston following violent assault on the adjacent train. Four heavily armed officers keep passing through the train searching for the aggressor, and nobody can leave the train."

A man has been arrested on suspicion of causing grievous bodily harm, British Transport Police (BTP) said.

Two people were taken to hospital with stab wounds after the incident.

The Rail, Maritime and Transport (RMT) union said one victim was a member of the RMT.

Avanti West Coast confirmed a member of its staff had been injured in the incident.

A BTP spokesman said: “British Transport Police were called to Euston railway station at 7.09am today following reports of a serious assault on-board a train.

“Specialist officers were deployed, and a man has been arrested on suspicion of grievous bodily harm and conveyed to police custody.

“Two people have been taken to a local hospital for treatment to laceration wounds. Their injuries are not believed to be life-changing or life-threatening.”

RMT general secretary Mick Lynch said: ”This is an appalling incident that will send shockwaves through the whole railway family, and our thoughts are with our member, his colleagues and his family this morning.

“While we await the full facts, the union will be providing practical support to our member and the workforce at Euston ‎as the police investigation continues.”

An Avanti West Coast spokesman said: “We can confirm a member of staff was injured following an incident at Euston station this morning and we are supporting the British Transport Police with their investigation.

“They are recovering in hospital and their family has been informed.

“We are providing support and assistance to our colleague and their family at this worrying time, as well as our people who have been affected by what has happened.

“Our thoughts are with our colleague, their family and everyone affected.

“We would also like to thank those from across the industry who have sent messages of support. It’s a true reflection of the Railway Family.”

Transport Salaried Staffs Association general secretary Manuel Cortes said: “This is a shocking incident and our union sends our thoughts and solidarity to those involved and their families.”