Police have arrested a 15-year-old boy in connection with a fatal knife attack in the west German city of Solingen.
The boy is not the main suspect but is alleged to have known about the attack beforehand.
Two men, aged 56 and 67, and a 56 year-old woman died in the attack on Friday, which German Chancellor Olaf Scholz called a “horrific act”.
The Islamic State group claimed responsibility for the attack. It did not immediately provide any evidence and it was not clear how close any relationship with the attacker was.
The 15-year-old connected to the case was detained this morning after two women reported overhearing a conversation between him and a second person in which they discussed the attack, the police said.
While he remains in custody, investigators are still trying to establish exactly who carried out the attack.
The suspect’s motive is unknown but police said they could not rule out that this was a “terrorist-motivated offence”.
Police say there was no specific terror threat before the festival and there was not a large security zone in place.
Chief of police Markus Röhrl urged people not to speculate on social media and appealed to the public for more information.
Police also revealed that they found “multiple knives” and were looking into whether one of them was involved in the attack.
The attacker reportedly stabbed passers-by “at random” during a festival to celebrate 650 years since the industrial city of Solingen was founded.
The situation on the ground after the attack was “very hectic”, which made it difficult to find a perpetrator, police said.
Police confirmed that the attacker “targeted” people’s throats and necks.
Germany’s Chancellor Olaf Scholz said that the assailant should be caught quickly and punished to fullest extent of the law.
Interior Minister Nancy Faeser expressed her condolences, adding that security authorities were “doing everything they can to catch the perpetrator and determine the background of the attack”.
Solingen – a city in North Rhine-Westphalia, which is famous for its steel industry – has about 160,000 inhabitants. It lies about 15 miles (25km) east of Düsseldorf.
The city’s authorities asked people to leave the Fronhof market area after the attack at about 22:00 local time (21:00 BST) on Friday.
In a Facebook statement on Friday night, Mayor Tim Kurzbach said: “Tonight all of us in Solingen are in shock, horror and great sadness.
“It breaks my heart that an attack has happened in our city. I have tears in my eyes when I think of those we’ve lost.
“I pray for all those still fighting for their lives. Also my greatest sympathy for all those who had to experience this, these images must have been horrific.”