RAMALLAH, West Bank - Palestinians protested across the occupied territories on the 60th anniversary of the "catastrophe" of the birth of Israel on Thursday as the Jewish state's army went on high alert.
The commemoration of the Naqba, or "catastrophe" -- the defeat of invading Arab armies and the expulsion or flight of about 760,000 people -- came as US President George W. Bush was to mark the creation of the Jewish state with an address to the Israeli parliament.
Thousands gathered in the West Bank political capital of Ramallah, waving Palestinian flags and demanding the "right of return" for some 4.5 million UN registered refugees scattered in camps across the Middle East.
Activists planned to release 21,915 black balloons -- one for each day since Israel's creation -- to darken the skies over Jerusalem during Bush's speech to the Knesset or parliament.
"On this good and beloved land live two peoples. One celebrates its independence and the other grieves in the commemoration of its Naqba," Palestinian president Mahmud Abbas said in a televised speech.
"Israel's security is linked to our independence and our security, and the continuation of the occupation and the persistence of the Naqba will not bring security to anyone."
About 3,000 people gathered in the heart of the northern West Bank city of Nablus holding keys -- real and symbolic -- to abandoned houses in what is now Israel and burning a US flag to protest Bush's visit.
For Palestinians the fate of the refugees lay at the core of the decades-old Middle East conflict and has bedeviled past peace efforts as Israel has refused to allow any of the refugees to return.
In the besieged Gaza Strip, where Hamas seized power nearly a year ago, the Islamist movement has called for a march to the Erez crossing with Israel to protest a "new Naqba" -- a crippling months-old blockade of the territory.
Since the armed movement -- which is pledged to the destruction of the Jewish state and has launched hundreds of crude, homemade rockets at southern Israel -- took power in June, Israel has sealed Gaza off from all but vital humanitarian aid.
Two-thirds of the 1.5 million people in impoverished Gaza are refugees, the vast majority of them living off UN food handouts.
Hamas spokesman Abdelatif Qanua said the demonstrators would not march to the heavily fortified crossing of Erez itself but to a customs office some three kilometres (two miles) from the border with Israel.
"This demonstration is not a storming of the border or of the Erez crossing. It's a normal, peaceful demonstration. If the enemy disperses it, it will bear full responsibility for that," Qanua told AFP.
Israeli forces have mobilised to prevent any "provocative acts" and Israel has previously warned Hamas against marching on the border.
"The IDF (Israeli military) has concentrated large forces in those areas suspected of demonstrations," Major Avital Leibovich told AFP.
The army "is planning to take strong measures against any provocative acts of Hamas that may cause damage to the security of Israel," she said.
Bush's visit, which is also intended to encourage the Middle East peace process, has already been marred by violence, with a Gaza rocket slamming into an Israeli shopping mall wounding 14 people, hours after Bush's arrival.
Israeli Arab lawmakers will be boycotting his speech to parliament, and Palestinians have expressed outrage at the decision to hold the event on their Naqba Day.
Bush is "responsible for the deaths of hundreds of thousands of people in the region," MP Jamal Zahalka, one of 10 parliamentarians from the three Arab political parties who will boycott the speech, said on Wednesday.
"His speech... shows complete indifference to the Naqba of the Palestinian people and its suffering."
Israel's three Arab parties draw support from the 1.2 million descendants of the 160,000 Arabs who remained in the Jewish state after the 1948 war.
© 2008 Agence France Presse