JERUSALEM, April 2 (Xinhua) -- Tens of thousands of people participated in the priestly blessing at the Western Wall of the Old City in Jerusalem on Monday during the Passover holiday, amid a popular Palestinian march against Israel.

The blessing is recited by Jewish people said to be descendants of Aaron, the brother of Moses, and is one of the most ancient blessings in the Jewish faith.

The kohanim, believed to be descendants of priests who served in the ancient Jewish Temple before it was destroyed, perform a mass blessing ceremony of the Jewish people three times a year during the festivals of Passover, Shavuot and Sukkot.

Passover commemorates the Israelite exodus from slavery in Egypt some 3,500 years ago.

The blessing was held during the time when Israeli-Palestinian tensions are running high. Heavy security measures were taken for the ceremony in the Old City.

The Israel Defense Forces announced a 10-day closure on all West Bank and Gaza border crossings from March 29.

On March 30, about 30,000 protesters from besieged Palestinian enclave marched towards the security fence separating the Gaza Strip and Israel.

The Israeli army responded with live ammunition and rubber-coated bullets, which claimed the lives of at least 15 Palestinians and injuring over 1,400.