JERUSALEM, May 13 (Xinhua) -- About 45,000 Israelis marched Sunday across Jerusalem amid high tensions to mark Israel's 1967 capture of East Jerusalem.

The annual parade, known as the "Flag March," was held under heavy police security a day before the United States was expected to move its embassy to Jerusalem.

The marchers, mainly ultranationalist religious Jewish youths, waved Israeli flags and blew horns as they passed through the Old City's Muslim Quarter en route to the Western Wall.

The parade is the main event of the "Jerusalem Day," an annual commemoration of the "reunification" of Jerusalem.

Israel seized East Jerusalem in the 1967 Mideast War, along with the rest of the West Bank and the Gaza Strip. It later annexed East Jerusalem and declared it as part of its "eternal and indivisible capital," in a move that has never been recognized by the international community.

Palestinians, who make up more than one third of the city's overall population, consider East Jerusalem as the capital of their future state.