EPAFour ancient gold artifacts were stolen from a Dutch museum during an overnight stay on Saturday morning.
Thieves used dynamite to blow up their way to the adult museum in Assen, which was hosting an exhibition of priceless Romanian jewels made of gold and silver.
They left behind three Dacian spiral bracelets and the central piece of the exhibition – the elaborately decorated helmet of cotofe Nesti, which was made some 2,500 years ago.
Romania’s Ministry of Culture has pledged to take all possible steps to recover the stolen items, which have been loaned from Bucharest to a Dutch museum.
Adult museum director Harry Tupan said the theft was “extremely shocking”, saying it was the largest incident in its 170-year history.
Police were called to the scene after an explosion occurred at 03:45 local time (04:45 GMT) on Saturday.
Officers conducted a forensic investigation and reviewed CCTV footage throughout the day.
Police are also investigating a burning vehicle found on a nearby road which they suspect may be linked to the break-in.
“It is possible that the suspect turned towards another vehicle in the vicinity of the fire,” a Dutch police statement said.
No arrests have been made, but authorities suspect multiple people were involved. Police have called global policing agency Interpol to help with the investigation.
Getty ImagesA statement from the museum said four “archaeological masterpieces” were plucked, including a Cotofe Nesti helmet from around 450 BC and three ancient Dacian Royal Bracelets.
All four stolen items are of huge cultural significance to Romania, and Cotofe Nesti’s helmet is considered a national treasure.
In the late 1990s, 24 bracelets from the same era were dug up by treasure hunters and sold abroad.
The Romanian state worked for many years to restore them from Austrian, German, French, British and American collectors.