Israeli nationalists marking the 1967 capture of East Jerusalem were to march through the Muslim quarter of the Old City on Thursday in an annual parade that Palestinians see as a provocation.
Here are details on "Jerusalem Day" and why it stirs fears of renewed violence:
WHAT IS JERUSALEM DAY?
Israel fought a number of Arab armies in a 1967 war, during which it captured territories including East Jerusalem. The annual commemoration can draw crowds in the tens of thousands.
Israel has since annexed East Jerusalem, in a move that has not won international recognition, and regards the entire city as its eternal and undivided capital. Palestinians want East Jerusalem as the capital of a future state.
The day's events culminate with a flag-waving march that cuts through downtown Jerusalem before entering the walled Old City, home to sites holy to Christians, Jews and Muslims.
In recent years, the parade has increasingly become a show of force for Jewish nationalists, and for Palestinians a blatant provocation meant to undermine their ties to the city.
WHY HAS IT CAUSED TENSIONS WITH PALESTINIANS?
The heavily-policed procession passes through the Old City's narrow streets, including areas that are popular among Palestinians such as Damascus Gate and the Muslim Quarter, forcing some Arab shopkeepers to close down. In the past, it has included some acts of racist incitement and violence.
Another source of tension has been visits by large groups of Jewish pilgrims, including members of parliament, to the Al-Aqsa mosque compound. Al-Aqsa is the third holiest site in Islam that Jews revere as the Temple Mount, a vestige of two ancient temples.
Palestinians say the visits and police enforcement around them are an Israeli attempt to encroach on one of the few places in the city where they sense a degree of sovereignty.
Muslims say Jewish visitors are also increasingly violating a decades-old ban on non-Muslim worship on the compound. Israel says it prevents such prayer and maintains the status quo.
HOW HAS THE EVENT LED TO VIOLENCE IN RECENT YEARS?
During the 2021 march, the Islamist Hamas group fired rockets into Israel, helping spark an 11-day war that killed at least 250 Palestinians in Gaza and 13 people in Israel.
Hamas, which governs blockaded Gaza, has cast itself in recent years as a defender of Jerusalem's Palestinians and Muslim holy sites. Ahead of Thursday's march, it has warned of an "explosion" if right-wing marchers violate the status quo at the Al-Aqsa mosque compound or attack Palestinians.
This year, Palestinians have also organised their own flag marches in the Israeli-occupied West Bank and Gaza, with some processions set to take place only a few hundred metres away from the Israel-Gaza separation fence.
(Writing by Henriette Chacar and Ari Rabinovitch; Editing by Andrew Cawthorne)
