Thieves stole four works attributed to Renaissance painter Antonello da Messina worth millions of euros from the regional museum in the city of Messina in Sicily while crowds gathered across town for the traditional Assumption holiday celebrations, cultural officials and Italian media said on Sunday.

The thieves bypassed alarm and security systems on Saturday evening at the MuMe museum, making off with three of the five surviving panels of the San Gregorio Polyptych, dated to 1473, as well as the double-sided panel depicting the Virgin Mary and the dead Christ in Pieta, which was removed from an armoured display case, the news agency LaPresse reported.

They removed all five panels of the San Gregorio Polyptych from their frame, but abandoned two behind a wall while fleeing.

Art expert Alberto Fiz estimated the value of the stolen works at €70 million to €80 million (US$81 million to US$92 million).

“We are devastated by what happened. They were two of Antonello da Messina’s most important and best-known works. It is a tremendous loss for the museum, the city, the community and the art world,” MuMe director Marisa Mercurio told the ANSA news agency.

She said the theft happened just before 10pm and described the works as central to the region’s heritage.