Two Swedish teenagers were jailed on Thursday in pre-trial detention in connection with two pre-dawn explosions in the vicinity of the Israeli embassy in Copenhagen a day earlier.

Prosecutors said investigators were establishing “whether the motive could be a terror attack”.

No one was injured in the blasts early on Wednesday in a neighbourhood with several foreign diplomatic missions, though the nearby Jewish school was closed following the explosions.

The two, who cannot be identified under a court order, were ordered to be held for 27 days.

Two police officers with dogs near the Israeli embassy in Copenhagen
Police investigating near the Israeli embassy in Copenhagen (Emil Helms/Ritzau Scanpix via AP)

They faced preliminary charges of possessing illegal weapons and carrying five hand grenades. Two of the grenades blew up when the suspects threw them at a house near the embassy, prosecutor Soren Harbo said.

“This was pretty close to the Israeli Embassy,” Mr Harbo said before Thursday’s court hearing. The explosions caused damage to a roof terrace of a nearby house. The diplomatic mission was not harmed.

Thursday’s hearing was held behind closed doors after the preliminary charges were read. Reporting from inside the court room, Danish broadcaster DR said the teenagers, aged 16 and 19, are suspected of acting “in association and together with prior agreement with one or more perpetrators”.

Both denied the charges, local media reported.

The two suspects were arrested on Wednesday shortly before noon on a train at Copenhagen’s central station. Danish media ran photos of a man in a white hazmat suit being taken away by police on a train platform at the station.

A third suspect, aged 19, who had been arrested near the embassy, has been released, police said on Thursday.

In Denmark, the charges are one step short of formal charges and allow authorities to keep criminal suspects in custody during an investigation.

In Stockholm, Fredrik Hallstrom from Sweden’s domestic security agency SAPO, said: “The latest incident at the Israeli embassy is not classified as a terrorist crime at the moment.”

His counterpart at the Swedish police’s National Operations Department, Johan Olsson, told the same press conference that the charges were of “aggravated weapons offences, causing danger or other serious illegal threats and damage”.

Separately, shots were fired late on Tuesday at the Israeli embassy in Stockholm. No one was injured. No arrests have been made.