A teenager has told a court how he "started laughing" when the Manchester Arena attacker encouraged him to study chemistry to learn how to make bomb.

The young man, who cannot be identified for legal reasons, was giving evidence in the trial of Hashem Abedi, 22, who is accused of plotting the May 2017 bombing with his brother Salman Abedi, who died in the blast.

In a police interview played in court, the witness, then aged 16, told of one occasion when he was in Hashem Abedi's car, accompanied by his brother and Salman Abedi.

Recalling the conversation with Salman, the student said: "He has told me stuff. We was in the car... 'do chemistry so you can build a bomb'.

"Before that he talked about martyring. He talked about Jihad. 'Jihad is beautiful'.

"And he was talking to me and he said to me, like he goes, basically not I wanna be a martyr but he was talking about how being a martyr was something big."

22 people were killed in the Manchester Arena attack. Credit: ITV News

He added: "I didn't used to think he was an inspiration in any way shape or form, do you know what I mean?"

Asked how he reacted to the bomb comment, the witness said: "I would not associate their family to be that type.

"I just looked and I did not even take it in. I looked out and started laughing.

"I laughed it off. He (Salman) might have laughed too. He might have said 'heh'.

"Even if he said to me 'I'm building a bomb' I would not have believed him. That's how insane it is, you know what I mean?"

The witness said he respected Salman even though he appeared "fatigued" and to "lack energy".

Hashem was like a "handyman" who liked to talk about fixing cars, jurors heard.

The trial continues.