Mr Haynes said he was not aware of Luke outside the vehicle

Colin Haynes, 59, of Gabalfa, Cardiff, denies causing death by dangerous driving after 13-year-old Luke Tanhai fell off the double-decker.

Cardiff Crown Court was told that Luke seemed to be playing a "game of dare".

Children claimed the driver ignored Luke and only stopped when he fell off, said the prosecution.

If he had actually stopped the bus then this could have been avoided Peter Heywood, prosecutor

The incident happened as pupils were leaving Cardiff High School in Lakeside last September.

The court heard that Luke, who suffered from attention deficit hyperactivity disorder, had been permanently excluded from the school that day.

He died from head injuries, possibly caused by the back wheels of the double-decker bus.

Peter Heywood, prosecuting, said Luke and two friends had climbed onto the outside rails of the bus as it moved away from the school in a game of dare.

Luke had been excluded from school on the day that he died

He said: "Mr Haynes was driving the vehicle dangerously because he must have been aware of the presence of all three boys clinging to the outside of the vehicle.

"If he had actually stopped the bus then this could have been avoided."

The court was told a passing motorist saw three youths hanging on to the side of the bus.

Two of the boys safely jumped clear of the bus.

'For the hell of it'

"It was his view that they didn't look like they were attempting to board it," said Mr Heywood.

"He thought they were doing it simply for the hell of it," Mr Heywood said.

"He describes them holding onto the rails by the doors at the front of the bus. It was his view that what they were doing was something like a game of dare."

Mr Heywood added: "Several children shouted to the driver saying he was there. But it appeared to them that the driver took no notice."

He told the court it was "abundantly clear" the three teenagers had placed themselves in a dangerous position by their actions.

The court heard Mr Haynes, a bus driver for 30 years, had told police he had had trouble with other children on the bus.

"Throughout his police interviews, Haynes maintains he was not aware of Luke outside the vehicle and only became aware after the accident when he was told by the children on the bus," Mr Heywood said.