Israel sought U.S. protection for its embassy here early Saturday, hours after thousands of Egyptian protesters besieged the building, with several managing to gain entry and fling Hebrew-language documents from a balcony.

Protesters knocked down a 12-foot concrete wall that had been built last week to protect the embassy, which is near the top floor of a 21-story residential building in the upscale Dokki neighborhood. At least two protesters scaled the front of the building to pull down the Israeli flag, hanging from the 20th floor. It was the second time in recent weeks that demonstrators had removed the flag.