ROME — The Italian news media called it a “movie-worthy heist.” In just a few minutes on Wednesday, the last day of an exhibition at the Ducal Palace in Venice, thieves made off with a gold brooch and a pair of earrings, easily disarming what had been described as a sophisticated alarm system and then disappearing into the sea of tourists who daily swarm St. Mark’s Square.

The jewels belonged to Sheikh Hamad bin Abdullah al-Thani, a member of the Qatari royal family. They were part of his collection of some 270 Indian and Indian-inspired gems and jewels, some dating from the 16th century, according to a news release for the exhibition, “Treasures of the Mughals and the Maharajas,” which opened in September.

The declared value of the stolen items on the customs form was 30,000 euros (about $36,000), but the Italian news media reported that they were most likely worth much more, as much as several million euros. Even so, the foundation that runs the museum told Italian reporters that the jewels were of less historical value than other items in the exhibition.