The Austrian police are investigating a report of sexual and physical assault perpetrated by four underage asylum seekers against three Austrian teenage school girls for months at the Scholassstrasse Middle School in Salzburg.

The teeners—three of them from Afghanistan, aged 14, 15 and 16, as well as a Syrian boy aged 16—have all been suspended after the school headmistress made a complaint to police, Mail Online reported.

The assault reportedly involves attacks and groping that started in November as well as verbal abuse and suggestive comments, said one of the victims who complained to the police, Austrian news agency Kronen Zeitung reported. It said the incident happened during the wake of sex attacks in Cologne, Germany.

According to the report, the girls were "repeatedly groped, but the final straw came when there was an attack so severe it forced action."

The paper said the 14-year-old victim was often hit by the 15-year-old boy, including an incident where she was hit so badly from behind that she smashed her head onto a desk.

She was again attacked Wednesday morning by the same boy smashing her against a locker so hard that the police were called, according to Kronen Zeitung.

"They took the victim and the accused to the station where the full story then came out. After hearing of her ordeal, police then expanded the investigation.''

Police in Salzburg said they are looking now into accusations of sexual assault, grievous bodily harm and making threats.

All the boys have been given asylum but have been suspended.

Despite the allegations, local education officials in the city reportedly played down the incident, saying it was nothing more than a few slaps in the corridor and "a few obscene comments that were speedily dealt with.''

The alleged sex assault happened after waves of sex attacks have been reported across continental Europe.

After hundreds of women were attacked by migrants in Germany during the New Year celebrations, reports of similar crimes also emerged from a number of other main cities.

Authorities and media have been accused of covering up the incidents for fear it could cause anti-immigration sentiments, reports said.