STOCKHOLM (AP) — Danish police say a powerful explosion has occurred outside a tax office in the capital, Copenhagen, shattering windows and damaging the building. No one is believed to have been injured.

Police said that the explosion happened late Tuesday.

Chief Police Inspector Jorgen Bergen Skov said in a statement that a “broad and comprehensive” investigation is underway but that “it is too early to say exactly who is behind the explosion.”

Police are calling on anyone with information relevant to the investigation to come forward.