LOS ANGELES—Authorities announced Tuesday that a dozen artworks from a multimillion-dollar art collection were stolen from the home of an elderly couple on August 23, the Los Angeles Times reports. The theft happened quickly on Saturday morning while the maid was out. A side door of the home was open, and the owners were sleeping in a room in a different part of the house.

"Somebody did this very quickly," said Detective Donald Hrycyk of the LAPD's art theft division.

Each stolen painting is worth at least six figures, some over $1 million, according to Richard Rice, a senior consultant at Gallerie Michael in Beverly Hills. Among the stolen works are Marc Chagall's Les Paysans, Diego Rivera's Mexican Peasant, Emil Nolde's Figur mit Hund (Figure with Dog), and Kees van Dongen's Alicia Alanova.

"A collection of this quality that is so specialized — these people had a passion," said Rice. He called the collection "a rarified group only sold at a small clique of galleries."

Police have announced a $200,000 reward for information leading to the return of the artworks. Officials did not release the victims' names or the crime's location; they did say that the paintings were insured by the couple, who made their money by investing in real estate, according to the Associated Press.

"It's just shocking that something like this would happen," Rice said. "I was saddened that someone could build such a collection and in a matter of minutes it could be gone."