Two teenagers, believed to be those accused of murdering Stefan Appleton, were seen acting “uncomfortably” in the minutes before he died, a court heard this morning.

Stefan, 17, was stabbed to death with a “zombie killer” machete in Nightingale Park, Canonbury, on June 10 last year. Two 17-year-old boys, both from the Islington borough but who cannot be named, are accused of his murder, which they deny.

Yesterday, the Old Bailey heard how Defendants One and Two arrived near the park on a moped. It is alleged “Two” jumped off, drew the machete, chased Stefan and stabbed him to death at 5.58pm. He and “One” then made their getaway.

Today, witness Tom Moran told how he was walking along Mortimer Road, near De Beauvoir Square, at 5.45pm when he saw two boys on a moped 10 yards away.

“They had a sense of being slightly uncomfortable,” he said.

“One said something along the lines of ‘let’s do this’ and they drove off. The way he said it was urgent.

“The person on the back of the moped zipped up his top to his nose. It meant you couldn’t see his face. On a summer evening, this was unusual.

“It made me feel uneasy.”

They drove towards Englefield Road, from which the prosecution alleges they travelled to Nightingale Park.

Yesterday, the court heard how Defendant Two accepts that he stabbed Stefan - but claims it was done in self-defence.

Defendant One, who transported his co-accused on a moped, also denies murder on the basis that he didn’t know anyone would be stabbed.

They, alongside a 16-year-old from Hertfordshire (Defendant Three), also deny a charge of conspiracy to cause grievous bodily harm.

The trial continues.