COLOGNE 

A German prosecutor questioned a suspect Friday for a deadly arson attack in the northwestern city of Solingen that killed a Turkish-Bulgarian family and injured more than one dozen people.

The prosecutor’s office said in a statement the suspect, who was detained after the attack on Thursday, was released following a lengthy interrogation but is still considered a possible suspect.

The statement did not reveal additional details about the suspect or the cause of the fire but said clues were obtained during the interrogation.

Police urged witnesses or anyone with information about the fire to contact authorities.

A fire Monday at a four-story house in Solingen killed a man, his wife and their two children, who were Bulgarian citizens of Turkish origin.

As many as 21 people were rescued from the building, with nine taken to the hospital with serious injuries, including two in critical condition.

Turkish nationals were among those injured.

1993 Solingen arson attack

Three decades ago, a far-right arson attack in Solingen killed five members of a Turkish immigrant family, in one of the most severe instances of racist violence in modern Germany.

Their house was set ablaze by neo-Nazis amid growing resentment against immigrants and foreigners, after the unification of East and West Germany.

Three girls, Saime Genc, Hulya Genc and Gulustan Ozturk, and two women, Hatice Genc and Gursun Ince, were killed, while 14 others, including several children, were wounded.

Police arrested four right-wing extremists who were sentenced to 10 - 15 years in prison.

They were released after serving their sentences.