The Islamic State group claimed responsibility on August 24 for a knife attack in the German city of Solingen that killed three people and wounded eight others, Report informs referring to Reuters.
Police have detained a teenager who may be connected with a knife attack, but the perpetrator was still at large on Saturday.
Describing the man who carried out the attack as a "soldier of the Islamic State", the militant group said in a statement on its Telegram account: "He carried out the attack in revenge for Muslims in Palestine and everywhere."
It did not immediately provide any evidence for its assertion and it was not clear how close any relationship between the attacker and Islamic State was.
Hendrik Wuest, premier of the state of North Rhine-Westphalia, described Friday evening's attack during a festival in the city as an act of terror.
Police were conducting a manhunt for the assailant. They said they had detained a 15-year-old and were investigating whether this person was linked to the attacker.
"This attack has struck at the heart of our country," Wuest told reporters.
Interior minister Nancy Faeser said authorities were doing all they could to catch the assailant.
The attack took place in the Fronhof, a market square in the western German city where live bands were playing as part of a festival marking the its 650th anniversary.
Markus Caspers, an official with the public prosecutor’s office in Duesseldorf, said authorities were treating the attack as a possible terrorist incident because there was no other known motive and the victims seemed unrelated.