A man with a large hunting knife being chased by police through Cardiff city centre was brought down by passers-by.
Muaz Tarafdar, 20, was riding a bike on Castle Street on Sunday, pursued by officers, when three men stepped in to help.
He was knocked off his bike and tripped up, allowing police to arrest him.
Tarafdar was sentenced to six months youth detention on Monday at Cardiff Magistrates’ Court after admitting possessing a knife in a public place.
Afterwards South Wales Police tweeted: “Thanks to those who put themselves in danger, especially the public who helped us on this occasion.”
After being pushed off his bike by one member of the public, Tarafdar was chased on foot by an officer and another passer-by.
A third man tripped him up and Tarafdar was brought to the ground and arrested.
He was later found to have a large hunting knife in his rucksack.
Andy Brown, who filmed the incident while he waiting at traffic lights in a car, said: “It was bit surreal. We were just sat at the traffic lights, saw a police van and a police car racing round the corner.
“Next thing he was taken down by a member of the public, right in front of me.
“You could almost see a couple of people lining up to take him off his bike, the second guy saw him coming and put a foot out to trip him up.”