Belgian police say they have questioned two Israelis after two pro-Palestinian groups alleged they had been waving flags from their army brigade at the Tomorrowland music festival.
The men were briefly detained and then released after they had been interviewed, prosecutors said.
The Hind Rajab Foundation and Global Legal Action Network said they had filed a complaint after a group of young Israelis was seen flying the purple-and-white flag of the Givati Brigade, alleging the pair had committed war crimes in Gaza.
The Givati flag was among several Israeli flags waved during a set by Israeli DJ duo Vini Vici at Tomorrowland last Friday.
Prosecutors said no further details would be released about the case at this stage. The Hind Rajab Foundation called the arrest of the Israelis a “significant step forward”.
They are not thought to have been prevented from leaving Belgium.
The BBC contacted the Israeli embassy in Brussels, which declined to comment other than to confirm that the two men had been released.
Before detaining the pair, prosecutors said they had decided they could investigate the allegations under Belgium’s universal jurisdiction law, which allows local courts to hear cases involving alleged crimes committed outside Belgium.
The law was updated last year to enable Belgian police to gather evidence of violations.
The European Jewish Association said in a statement that it was “deeply concerned” by the conduct of the Belgian authorities towards the two Israelis.
“These soldiers were carrying out their lawful duties in defense of their country, duties comparable to those of any soldier serving in a democratic nation,” the EJA said.
The Hind Rajab Foundation is chaired by Dyab Abou Jahjah, a controversial Belgian-Lebanese activist who has admitted joining Lebanese group Hezbollah when he was young. Hezbollah’s military wing is proscribed as a terrorist group in the EU.
This year’s Tomorrowland festival went ahead last week even though a fire destroyed the main stage 48 hours before the event was due to start.
Tens of thousands flocked to the festival in Boom, near Antwerp, to hear acts including David Guetta and Lost Frequencies.
