A passenger aboard a train where a mass stabbing occurred has told a court he initially feared a suicide bombing. Milan Campion was traveling on a London-bound LNER service on 1 November last year when it made an unscheduled stop at Huntingdon during an attack by Anthony Williams, Cambridge Crown Court heard.

Campion testified that Williams was "threatening everyone indiscriminately," leading him to conclude that Williams was "not sound of mind." Williams, 33, of Peterborough, denies 10 counts of attempted murder on the train and four other attempted murders in earlier incidents in Peterborough and London.

In a video interview played to jurors on Monday, Campion recounted boarding the train at Grantham, noting that "quite a lot of us had travelled from the Nottingham Forest versus Manchester United game." He described opening a toilet door to find Williams inside, sitting and staring at the ground, which he found odd because the door was unlocked.

Later, Campion heard shouts of "there's a guy with a knife" and joined a "big chain of us running down the aisle shouting to follow us." He said, "I thought it was a bomb at first. I thought it might have been a suicide bomber so I need to get as far away as possible to maximise your chance of survival if it goes off."

Campion also spoke to Williams in the catering section, telling him, "you can't win - what you trying to do?" and "it's not worth it." He described Williams as "remonstrating with no-one in particular" and shouting something he couldn't discern. "He just looked angry, you could see the anger in his eyes," Campion said.

Another witness, Dinaria Soares, was sitting across from footballer Jonathan Gjoshe, the first person attacked on the train. She saw the knifeman "hit him on the shoulder... I was surprised and confused at first." When the attacker pulled his arm back, she saw a knife and described a "stabbing motion had a lot of force behind it." She then fled to the front of the train where people were "trapped like sardines as there was nowhere else to move."

The prosecution has alleged that Williams "has some mental health issues which may or may not become relevant during this trial." In addition to the train charges, prosecutors claim that on 31 October he tried to kill three people in Peterborough, and on 1 November he attempted to murder a teenager on a DLR train in east London.

Whether Williams carried out the attacks is not in dispute, the court has been told, but jurors must determine whether he intended to kill. The trial continues.