An annual day of Palestinian grievance comes amid the upheaval.

The convulsions in Israel and the Palestinian Territories were afflicted with an additional source of angry emotion on Saturday as the Palestinian diaspora and its supporters recalled Nakba Day, which marked the displacement of hundreds of thousands of Palestinians in 1948 amid Israel’s declaration of independence.

Every year on May 15, Palestinians and their supporters protest against what Palestinians call nakba, which means disaster. This term describes the upheaval 73 years ago when the State of Israel was founded.

In November 1947, the United Nations passed a plan to partition compulsory Palestine, as the region was called under British control. The plan, accepted by Jews and rejected by Arabs on the territory, would have created separate independent Jewish and Arab states with an international regime to oversee Jerusalem. Immediately after the resolution was passed, war broke out between Jews and Arabs.

Until 1998, not a single day was chosen by the Palestinians to commemorate and protest what happened, although many took advantage of Israel’s Independence Day to mark the events.

As Israel was preparing lavish 50th anniversary celebrations that year, the President of the Palestinian Authority, Yasir Arafat, decreed that the Palestinians should have their own memorial day: May 15, the day after Israel gained independence in 1948 Israeli holiday based on the Hebrew calendar does not fall on the same day every year in the Gregorian calendar. That year, Israel’s Independence Day was in mid-April.)

The United Nations Aid, founded in 1948 to help displaced Palestinian refugees, is now providing assistance and services to 5.7 million Palestinians and their descendants in camps in the occupied territories adjacent to Israel and elsewhere in the Middle East.

The Palestinians in the West Bank, Gaza Strip and East Jerusalem were joined on Saturday by activists around the world who view Israeli politics as increasingly oppressive. A Facebook post by the Palestinian Youth Movement promoted North American rallies in 22 cities. Demonstrations were also planned in Africa, Europe and elsewhere.