A 14-year-old boy has died and four people have been wounded in a knife attack in Austria.

It happened at around 16:00 local time (15:00 GMT) near the main square of Villach, a southern town close to the border with Italy and Slovenia.

The suspect is a 23-year-old Syrian asylum seeker and has been detained, AFP news agency reported citing a police official.

“A man randomly attacked passers-by with a knife,” police spokesman Rainer Dionisio told AFP.

A delivery worker who drove his vehicle at the attacker helped prevent more injuries, the police spokesman told ORF, Austria’s national broadcaster.

Police have not ruled out a second attacker being involved, ORF added.

Austrian media reported the suspect, whose identity has not been confirmed by police, may have had a valid residence permit.

The broadcaster said two of the four people injured were in a serious condition.

Any motive or link between the knifeman and five victims are not yet known, though ORF reported extremism police had been drafted in to investigate.

Governor Peter Kaiser of Carinthia – the region where Villach is located – described the attack as an “unimaginable atrocity”.