Israeli security forces were on high alert on Sunday after warnings by <a href="https://www.thenationalnews.com/tags/hamas/" target="_blank">Hamas</a> of violence as Palestinians and Israeli Arabs are set to mark an important date in the calendar. <a href="https://www.thenationalnews.com/mena/2022/05/11/nakba-day-what-happened-in-the-palestinian-nakba-of-1948/" target="_blank">Nakba Day</a> on May 15 commemorates the displacement of thousands of Palestinians after the founding of the Israeli state in the aftermath of the Second World War. Israel was formed in 1948, which led to at least 700,000 Palestinians being forced to flee and seek refuge in neighbouring Jordan, Lebanon, Syria, the <a href="https://www.thenationalnews.com/weekend/2022/05/06/palestinian-villagers-scarred-by-year-of-protests-against-israeli-settlers-in-west-bank/" target="_blank">West Bank</a> and the <a href="https://www.thenationalnews.com/mena/2022/05/15/israel-reopens-gaza-crossing-for-palestinian-workers/" target="_blank">Gaza Strip</a>. Hamas, the militant group that rules Gaza, said violence was inevitable and the “Zionist occupier” would be held responsible after Israeli statements that called for Jews to storm <a href="https://www.thenationalnews.com/mena/2022/05/05/israeli-police-confront-palestinian-protesters-at-jerusalems-al-aqsa-mosque/" target="_blank">Al Aqsa Mosque in Jerusalem</a> on Sunday. Hamas spokesman Hazem Qassem said: “The extremist statements calling on [Jews] to storm the Al Aqsa Mosque on Nakba Day are a dangerous escalation that constitutes a provocation towards our people, which will result in clashes that the Zionist occupier will be held responsible for." Jerusalem’s Al Aqsa Mosque compound is the third-holiest site in Islam and the most important site for Jews, who are permitted to visit but not pray at the complex. The compound sits above the Western Wall, which is the focal point of Jewish prayers in Jerusalem. “We call on the masses of our people in Jerusalem, the West Bank and occupied Israel to come to the Al Aqsa Mosque and foil the occupation’s evil plans,” Mr Qassem said. Confrontations between Palestinian protesters and Israeli police at the site take place regularly. Last year, Gaza militants and Israel fought an 11-day war, after weeks of violence at Al Aqsa and elsewhere in occupied East Jerusalem. The warning by Hamas comes as tension was heightened by the killing of renowned <a href="https://www.thenationalnews.com/mena/2022/05/14/israel-orders-inquiry-into-officers-actions-at-shireen-abu-akleh-funeral/" target="_blank">Al Jazeera journalist Shireen Abu Akleh</a> last week in the northern West Bank city of Jenin. Her death came during violence between Palestinian gunmen and Israeli forces as an Israeli arrest raid took place. Al Jazeera and the Palestinian authorities blame Israeli soldiers for her death. Israel initially blamed Palestinian gunmen before backtracking, saying it was difficult to determine who was responsible. Israeli authorities said they were investigating. The US, EU, UN and regional countries have called for a full investigation into what Al Jazeera called a deliberate killing “in cold blood”. The Palestinian Authority has rejected the prospect of holding a joint probe with Israel.