Thieves stole a painting by Dutch Golden-Age master Frans Hals from a small museum near the Dutch city of Utrecht on Thursday, police said, the third time the canvas has been stolen.
The artwork, valued at 15 million euros ($18 million) by one expert, and dating from 1626, was taken from the Hofje van Aerden Museum before dawn on Thursday with thieves breaking into the building from the back door.
It is the second theft of a painting from a Dutch museum closed to the public because of the COVID-19 pandemic, after a Van Gogh was stolen from the Singer Laren Museum in March.
"Around 3:30 a.m. the alarm went off, and agents went straight to the museum," police said in a statement, calling for witnesses. "After the museum's manager could grant access to the area and building, it emerged that the back door had been forced open and one painting had been stolen."
A spokesman for the museum referred all questions to the police.
RTL Nieuws cited art expert Arthur Brand as estimating the painting's value at around 15 million euros ($18 million).
"Criminals know that major museums have sufficient security," he told the Dutch broadcaster, but smaller regional museums less so.
"They probably concluded it's worth a lot of money, and it's relatively easy to steal."
'Two Laughing Boys' has been stolen twice before in its four-century history, including as recently as May 2011 from the same museum. Police recovered it later that year after arresting four men who tried to sell it.
The Van Gogh painting taken in Laren, the 1884 "Spring Garden," has not been recovered.
Hals, a contemporary of Dutch painter Rembrandt van Rijn, was born in the early 1580s in Antwerp and moved as a child to the Dutch city of Haarlem. He began to work as an art restorer before becoming a portrait painter in his own right. He is best known for his painting "The Laughing Cavalier" as well as some of his life-size group portraits. He died in Haarlem 1666.