German police prevented a suspected arson attack by neo-Nazi extremists targeting a refugee shelter in northern Germany, authorities said Monday.

A 15-year-old suspect is in pretrial detention on charges that include preparing a terrorist act, public broadcaster NDR reported, citing authorities.

The Lueneburg prosecutor's office confirmed that police had searched the homes of two suspects, who were under investigation for allegedly conspiring to commit arson.

Police detained the teenager after witnesses reported seeing him walking through a town carrying a gasoline canister.

Investigators found that the incident coincided with the date mentioned in online chats as the planned time for an arson attack on a refugee shelter in Winsen, in the northern state of Lower Saxony.

The chats reportedly involved young neo-Nazis discussing plans to attack the shelter on a Friday night.

The Flensburg prosecutor's office said Monday that the 15-year-old remained in custody.

Beyond the suspected arson conspiracy, investigators accused the teenager of preparing a serious terrorist act and expressed concern that he could commit similar offenses if released.