The US embassy in Oslo sustained minor damage after it was hit by an explosion early on Sunday, Reuters reported, citing Norwegian police speaking to local media. No injuries were reported.

Police spokesperson Mikael Dellemyr told public broadcaster NRK that the blast occurred at the entry of the consular section of the embassy, adding that a search for suspects is underway, Reuters reported.

Eyewitnesses told local media that they heard a loud explosion near the embassy complex in western Oslo at around 1 a.m. local time, the news agency also reported.

It is not immediately known who was responsible for the attack. CNN has reached out to the embassy and the State Department for comment.