Palestinians protesting against an Israeli-led blockade formed a human chain on Monday along roads in the Hamas-controlled Gaza Strip and Israel threatened to use force if they tried to surge into its territory.
Hundreds of women and children, many holding Palestinian and Hamas flags, turned out for the start of what organisers said they hoped would be a peaceful protest involving some 50,000 people and draw international attention.
Last month, Israel tightened the blockade on the territory, home to 1.5 million Palestinians, limiting supplies of fuel and other goods.
"We call on the liberals of the world to rescue Gaza from darkness," one protest banner read.
Israeli troops garrisoned along the closely monitored, fenced frontier with the Gaza Strip were on high alert and paramilitary riot police on standby.
"I hope that, ultimately, they understand that we are deployed and ready, that this will not be a repeat of what happened in the Philadelphi Corridor (Egypt border) a few weeks back," Deputy Defence Minister Matan Vilnai told Israel Radio.
Hamas blew open Gaza's border wall with Egypt last month, allowing hundreds of thousands of Palestinians to cross into Egypt and stock up with food and other goods.
Asked if Israeli forces might resort to live fire, Vinai said: "Anything that must be done, will be done."
Hamas and an allied group organising the rally said the crowd would not try to storm the Israeli border.
Güncelleme Tarihi: 25 Şubat 2008, 17:12
"But they will show the world that the siege must be broken," said Jamal al-Khudary, chairman of the Popular Anti-Siege Committee.
He said protesters were under instructions to stay 1 km (1/2 mile) from the border and would be monitored by police.
Israeli media reported that military reinforcements on the Gaza border included artillery cannon armed with smoke shells that could be fired to disperse crowds.