For the first time in the 53 years since the modern state of Israel was established, sirens wailed out across Palestinian territory to mark the "catastrophe" of that event - and hundreds of thousands of Palestinians, along with Arab schoolchildren inside Israel, rose in silence for Nakba.
The midday sirens and three minutes of quiet, however, were only a minor respite from yet another day of violent Israeli-Palestinian confrontation, in which at least four Palestinian men and an Israeli girl were killed.
Two Palestinians died in clashes with Israeli troops in the Ramallah area. An Israeli tank shell in Gaza killed two more.
One of the two, Abdel Karim Maname, - who were allegedly setting up a mortar to fire on an Israeli settlement - turned out to be a personal bodyguard of Sheikh Ahmed Yasin, leader of the radical Hamas movement. Hamas swore revenge, promising "our reaction will be like an earthquake that will rock the ground under the feet of the Zionists".
Last night, an Israeli girl was shot dead by Palestinian gunmen in the West Bank; her father and brother were also injured in the attack.
Ministers in the Palestinian Authority, leaders of the armed Tanzim militias, and Arab members of the Israeli Knesset all participated in Nakba day marches. The presence of Knesset members including Mr Ahmed Tibi, a former political adviser to Mr Yasser Arafat, at various rallies prompted calls from some members of the Israeli government for the banning of their parties. Mr Tibi was also removed from the Knesset podium yesterday after he called Israel's Army Chief of Staff, Gen Shaul Mofaz, a "murderer" and a "fascist".
Mr Tibi made the comments following the killings by Israeli troops on Monday of five Palestinian policemen near a roadblock outside Ramallah. Gen Mofaz acknowledged yesterday that their deaths had "not been the intended result". Israeli Television has reported that the soldiers shot the policemen, unprovoked, as part of a "revenge operation".
Mr Arafat chose to leave Gaza on Nakba day, flying to Egypt for talks with President Mubarak. In a recorded address broadcast on Palestinian Television, Mr Arafat castigated the "executioners" who "walk through the puddles of our blood . . ."
He said that the Palestinians would only sign a peace accord that gave them all the territory captured by Israel in the 1967 war and a "right of return for those who were forced to flee their houses when the state of Israel was established".
Mr Arafat has accepted a proposal by the Mitchell Commission, the US-led international inquiry team into the violence, for a ceasefire that would include a freeze on Israeli settlements. Israel yesterday accepted the commission's proposal in principle - the Foreign Minister, Mr Shimon Peres, called it "positive" and "balanced" - while raising objections to the demand for a freeze.
Nevertheless, behind the scenes, the Israeli government is apparently indicating a willingness for at least a temporary freeze, and it is now likely that the Bush administration will use the Mitchell proposal as the basis for a new diplomatic initiative.
However, the Internal Security Minister, Mr Uzi Landau, is already protesting that Mr Arafat would be "rewarded for violence" if settlement construction were halted. A coalition split on the issue is looming.