Four ancient gold artifacts were stolen from a Dutch museum in an overnight raid in the early hours of Saturday morning.

Thieves used explosives to break into the Drenthe Museum in Assen, which was hosting an exhibition of priceless Romanian gold and silver jewellery.

They left behind three Dacian spiral bracelets and the centerpiece of the exhibition, the beautifully decorated Cotofenesti helmet, which was made nearly 2,500 years ago.

Romania’s Ministry of Culture has pledged to take all possible measures to recover stolen items loaned to a Dutch museum from Bucharest.

Harry Tupan, director of the Drenz Museum, said staff were “absolutely shocked” by the break-in, which he said was the largest in the museum’s 170-year history.

Police rushed to the scene after reports of an explosion at 03:45 local time (04:45 GMT) on Saturday.

Police conducted forensic investigations 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.

“One possible scenario is that the suspect swerved into another vehicle near 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 assist with the investigation.

A statement from the museum said four “archaeological masterpieces” were stolen, including the Cotofenesti helmet, which dates to around 450 BC, and three ancient Dacian royal bracelets.

All four stolen items are of great cultural significance to Romania, with Cotto Finnesti’s helmet 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 government has been working for years to recover the artifacts from collectors in Austria, Germany, France, the United Kingdom and the United States.