Education authorities are warning of a deadly choking game that has reached New Zealand.
The fad, which has plagued America and Britain for years, has now made its way to Hawke's Bay playgrounds, Hawke's Bay Today reported.
The game involves young people hyperventilating to create a mild rush when oxygen is returned to the brain.
Sometimes children have their chests squeezed until they faint.
The choking has reportedly caused hundreds of deaths overseas.
Hawke's Bay Public Health Unit paediatrician and clinical director of maternal, child and youth service, Russell Wills, was concerned enough to send an advisory to local schools, asking principals to warn students of the dangers.
"It is better that principals are aware of it and can deal with it firmly and immediately and also so they understand the risks," he said.
British doctors have warned the choking game can lead to seizures, head injuries, strokes, heart failure and brain damage.
Mr Wills said it appeared the practice was most prevalent in secondary schools among Year 9 to 11 students and boys.
Warning signs that students may have tried the game included bloodshot eyes, marks on the neck, frequent severe headaches and disorientation after spending time alone.
Ropes, scarves and belts tied to bedroom furniture or doorknobs or found knotted could also be a sign a student may have tried it.
Campaign group Games Adolescents Shouldn't Play said up to 458 children in the US and 86 in Britain had been killed this way.
It was known by several names including "space monkey" and "funky chicken".