Katerina vividly recalls the day a younger boy from a nearby school pressed a knife to her friend's throat.

Underage crime in Greece is on the rise, official data shows, presenting authorities with a challenge they have never faced at this level before.

"He can't have been over 14 years old -- my friend was cracking jokes, he didn't take him seriously at first," said the 16-year-old girl in the capital Athens, who asked to be interviewed under a false name.

"That boy peeled off from a group of 20 kids and demanded my friend's cellphone," she said, recalling the event two years later.

According to police figures, robbery with violence committed by minors aged 13 to 17 rose from 62 in 2000 to over 470 in 2020, while homicides more than doubled from seven to 16, and rapes increased fivefold from six to 32.

With school brawls breaking out on a regular basis, police minister Giannis Oikonomou was summoned to parliament on November 6 to address the issue.

He said a "culture of violence" was growing among youths in Greece, with often "shocking" results.

"It reflects a failure of family, of school, of society in general," Oikonomou said, adding that police had arrested around 1,300 youths for various crimes and misdemeanours in September.

"It is particularly worrying that the average age of perpetrators is falling," Oikonomou said.

Experts and officials blame factors including Greece's near-decade economic crisis, and the coronavirus lockdown, for the spread of youth alienation that countries such as Britain, France and Germany are already familiar with.

France in 2020 recorded 357 youth gang incidents compared to 288 the previous year, and the interior ministry has identified 74 gangs around the country, 46 just in the Paris region.

In Britain, the Children's Commissioner in 2019 estimated that 27,000 children in England alone identified as gang members.

Germany, where nationwide figures are harder to come by, has also been shocked by teen killings in recent years.

School bullying in Greece is also turning nastier and more frequent, with cases making headlines every week.

A study in March supervised by the European Antibullying Network found that one in three Greek school children among nearly 3,000 polled had suffered bullying -- mainly at the ages of 13 and 14, and primarily directed at girls, migrants and those from single-parent families.

One in six also said they felt their school was not providing adequate instruction against bullying.

Much of the violence goes unreported.

"Nobody calls the police -- you don't want to get in trouble," Katerina said.

In June, eight minors were convicted of gang raping a 15-year-old boy in the western Athens district of Ilion.

In September, a 16-year-old boy threw a lit flare into a classroom in Langadas, near Thessaloniki.

And in November, three teenage girls were arrested for beating a classmate in a schoolyard in the Athens district of Peristeri.

In addition to the 2010-2018 economic crisis that shook the nation, Covid restrictions and the influence of social media are seen as key factors.

"The economic crisis, and the pandemic crisis immediately afterwards, played a major role in children being closed off and feeling very uncomfortable without their friends," Nestor Courakis, a criminology expert and professor of law at the University of Nicosia in Cyprus, told AFP.

"The result is that they went online, with all that entails in terms of isolation, depression and negative influences," he said. "Youths have become more familiarised with violence."

"But the situation is not out of control," Courakis insisted.

Katerina's mother, who also declined to give her name, said the working-class Athens district where the family lives was hit hard by the economic crisis.

"And teens experience economic hardship more than adults do," she said.

She also blames the growing influence of trap, a subgenre of hip-hop featuring lyrics that detractors say promote violence and objectify women.

"They play trap even at parties in our local primary school, for children younger than nine," she said.

The government says it has doubled the number of psychologists and social workers at schools to 3,200, and a law passed in March foresees additional training to around 125,000 teachers nationwide.