Three young Swedes have been arrested in connection with two explosions in the vicinity of the Israeli embassy in Copenhagen, prompting a nearby Jewish school to close for the day.

Police said no-one was injured in the pre-dawn incident, with the blasts “likely to have been caused by hand grenades”.

Jens Jespersen, a spokesman for the Copenhagen police, said it was unclear whether the Israeli embassy was the target. The blasts occurred at around 3.20am local time (2.20am BST).

The spokesman said the explosions were about 100 yards from the embassy, which is located in an area which hosts other embassies. The blasts also affected another building, but Mr Jespersen did not provide further details on the damage.

The suspects were aged between 15 and 20, Mr Jespersen said, with one arrested near the embassy while the two others were detained on a train at Copenhagen’s central station. They were not identified.

Military police officers stand guard
Three Swedes aged between 15 and 20 have been arrested (Scanpix via AP)

The two arrested on the train will likely face preliminary charges of illegal weapons possession, he said. Any preliminary charge could be expanded later.

The Ekstra Bladet newspaper ran photos of a man in a white hazmat suit being taken away by police on a train platform at the central station.

After the explosions, heavily armed officers, search dogs and forensic teams inspected the area around the Israeli embassy.

Michael Rachlin, a spokesperson for Denmark’s Jewish community, said Copenhagen’s Jewish school, Carolineskolen, which is just down the street from the embassy, was already scheduled to be closed on Thursday and Friday for the Jewish New Year holidays.

There will be extra security around the main synagogue in downtown Copenhagen, the Jewish community said in a statement.

Community chairman Henrik Goldstein wrote that he “would like to encourage people to be aware when moving in public spaces. And be critical of what you hear on social media and rumours”.

Police investigate explosions near the Israeli embassy in Copenhagen
Investigations are contining (Scanpix via AP)

He added that “there is no reason to refrain from participating in Jewish life”.

Police refused to provide details about the intensity of the blasts.

Danish Justice Minister Peter Hummelgaard told broadcaster TV2 that the incident was “inherently serious,” adding that it was too early to say anything about a motive.

Mr Jespersen said the Danish investigation will include looking at what Sweden’s domestic security agency SAPO said on May 30, when it accused Iran of using established criminal networks in Sweden as a proxy to target Israeli or Jewish interests in Denmark.

The investigation will also look at possible links with loud bangs that were heard in the area around the Israeli embassy in Stockholm late Tuesday, he said. Police later announced that findings from the scene indicated the embassy was hit by bullets. No-one has been arrested, they said.

Swedish broadcaster TV4 said a weapon and an empty shell casing were found at or near the embassy.