UK mass train stabbing: What we know about horrific attack

Questions continue to swirl after a horrific mass stabbing on a UK train put 11 people in hospital .

Police have yet to lay charges over the incident, though one man remains in custody.

Here's what we do know about the attack.

What happened? 

At about 7.42pm Saturday night local time (6.42 am Sunday AEDT) passengers aboard a London-bound train from Doncaster made the first emergency calls to police, with reports of people fleeing through the carriages and seeking shelter in the train toilets.

The train driver, since identified as a war veteran, pulled the train in to an emergency stop at Huntingdon, about 120km north of London.

Police swarmed the train and arrested two men at about 7.50pm local time, just eight minutes after the first emergency calls.

Ten people were tak