Conductor Daniel Barenboim has called off two concerts in Qatar and Egypt.
He said the concerts have been axed "due to the escalating violence in Gaza and the resulting concerns for the musicians' safety".
Barenboim had been due to appear with his West-Eastern Divan Orchestra on 10 January in Doha, Qatar, with a second date in Cairo, Egypt, two days later.
Instead, the Arab-Israeli ensemble will now begin its 10th anniversary concert tour in Berlin on 12 January.
The remainder of the tour will proceed as planned, with scheduled dates in Moscow, Vienna and Milan unaffected.
Born in Argentina, the 66-year-old conductor grew up in Israel and is known for his championing of Palestinian rights.
At a New Year concert in Vienna on 1 January, he said he hoped 2009 would be a "year of peace in the world and of human justice in the Middle East".
Barenboim founded the West-Eastern Divan Orchestra in 1999 with the late writer Edward Said to further cultural exchange between young people in Israel and the Arab world.
Last year, the musician announced he had accepted honorary Palestinian citizenship.