Police in Catalonia are removing medieval artefacts in an ownership battle with neighbouring Aragon.
The operation, which started at 04:00 (03:00 GMT), will seize 44 items stored in the Catalan Museum of Lleida but originally from Sijena convent.
Aragon claims they were sold illegally by the convent’s nuns.
The operation, ordered by Spain’s culture ministry, comes as tension over Catalan independence moves continues. Dozens protested outside the museum.
The legal dispute over the items dates back to the 1980s.