Burglars stole a Stradivari violin worth at least € 2 million ($ 2.7 million) and another valuable instrument breaking into a musician's wall safe.

Police said the estimated value of the Stradivari could be as high as € 2.5 million ($ 3.36 million). Also stolen from the musician's Vienna apartment was a Vuillaume violin worth an estimated € 120,000 ($ 161,500), as well as three valuable bows, law enforcement officials said.

"It's clear that the perpetrators were total professionals," police official Walter Blesky told the Austria Press Agency. "Cutting open the safe was a pile of work."

Police did not identify the victim, other than saying he was a 49-year-old musician who was participating in a chamber music recital in Germany when the break-in occurred.

Antonio Giacomo Stradivari is considered the world's master builder of violins and other string instruments, crafting more than 1,000 of them in the 17th and 18th centuries. Approximately 600 Stradivarius instruments are still in existence. Some are displayed in museums, while others are still played by the world's top string virtuosos.