(SOLINGEN, Germany) -- German police said they have detained a 15-year-old boy and are working to verify if the teen is connected to the stabbing of several people at a music festival in Solingen on Friday.
Three people were killed in the attack and eight others were injured -- four of whom are considered "very seriously injured." Police are continuing to search for the attacker.
The people killed in the attack include two men ages 67 and 57 and a woman aged 56, authorities said.
ISIS took credit for the attack on Saturday, according to Site Intelligence Group, an NGO that specializes in tracking jihadist media. It's unclear how closely the unknown attacker was affiliated with the terrorist group or an affiliate group at this time.
The 15-year-old arrested in the early hours is being accused of "failure to report planned crimes," but he has not been charged, Markus Caspers, the Duesseldorf prosecutor general, said during a press conference Saturday.
Two female witnesses overheard a conversation between the 15-year-old and another person that could have indicated the attack, and they reported this information to the police after the incident, according to Caspers.
Police are continuing searches in "various locations" and are looking for potential perpetrators, police said in a press conference Saturday. Police currently believe the individual was acting alone.
Police said they found several knives at the scene and believe the attacker may have been targeting the necks of his victims.
Authorities are still investigating the motive behind the attack but said the victims had no apparent relationship to another and investigators suspect this may have been an act of terrorism, according to Caspers.
The "Festival of Diversity" was being held throughout the weekend to celebrate Solingen's 650th anniversary, according to the festival's organizers.
Prior to the festival, police said they had no information regarding a threat, so there were no surveillance zones or similar measures in place. They said they will be more thorough with security concepts in the future.