Gold bracelets and a helmet featured in an exhibition about the Dacians, an ancient people from present-day Romania and Moldova, were stolen on Friday night from a museum in the Netherlands.
The Drents Museum in Assen was showcasing over 600 artefacts, some of which date back to 2000 BC.
The thieves used explosives to break into the museum. They took three gold bracelets and a gold helmet, which was the centrepiece of the exhibition. Several display cases were smashed during the robbery.
At least 15 Romanian museums had lent items to the Dutch museum for the exhibition.
"This is an incredibly dark day, and we are deeply shocked," said museum director Harry Tupan. "We are profoundly saddened that our Romanian colleagues' treasures have been stolen. This is not just about gold, but cultural heritage."
Police are searching for a suspicious vehicle and have asked local residents to provide any footage they might have of the explosion.
