The explosion was likely caused by some kind of explosive device.
Danish police are investigating the incident extensively and looking into whether there is a connection to the bombing at the embassy last week.
At present, there is nothing to suggest that, says Trine Møller at the Copenhagen police during a press conference.
She emphasizes that it is one year since Hamas' terrorist attack on Israel.
It will be marked in many places around Copenhagen, and therefore we will be present.
The Copenhagen police do not want to disclose whether anyone has been arrested for the explosion.
Several neighbors to the stairwell where the explosion occurred have told Danish media that they were woken up by a loud bang at around 3 am last night.
On Wednesday, a bombing occurred near the embassy, and two young Swedes, 16 and 19 years old, are suspected of terrorist offenses. The Danish police have previously stated that the target was most likely Israel's embassy.
