Fresh protests against Israel are expected in the Palestinian territories on Tuesday, a day after Israeli troops killed 58 people in the Gaza Strip.
Monday was the deadliest day since a new wave of protests began at the Gaza border fence seven weeks ago.
Tuesday marks the 70th anniversary of what Palestinians call the Nakba - the mass displacement of Palestinians in the war following Israel's creation.
Renewed tension is expected in Gaza, as the dead are buried in the enclave.
Monday's violence came as the US inaugurated its first embassy in Jerusalem, a controversial move which has incensed Palestinians.
They claim East Jerusalem as the capital of a future Palestinian state and see the US move as backing Israeli control over the whole of the city - which Israel regards as its indivisible capital.
Palestinian officials said that, as well as those killed, about 2,700 people were injured in Monday's violence - which they condemned as a massacre. It was the deadliest day in Gaza since the 2014 war.
Israeli PM Benjamin Netanyahu said his military was acting in self-defence against Gaza's Islamist rulers, Hamas, who he said wanted to destroy Israel.
What happened at the Gaza border?
Palestinians were demonstrating on Monday as they have been for six weeks as part of a protest, orchestrated by Hamas, called the "Great March of Return".
However, Monday's protests - and those planned for Tuesday - are the culmination as they mark the anniversary of Israel's creation in 1948 and commemorate the hundreds of thousands of Palestinians who subsequently fled their homes or were displaced in the war that followed.
Israel said some 40,000 Palestinians had taken part in "violent riots" at 13 locations along Israel's security fence along Gaza's eastern border.
Palestinians hurled stones and incendiary devices, while the Israeli military used tear gas and live fire from snipers.
Mr Netanyahu defended his military, saying: "Every country has an obligation to defend its borders.
"The Hamas terrorist organisation declares its intention to destroy Israel and sends thousands to breach the border fence in order to achieve this goal. We will continue to act with determination to protect our sovereignty and our citizens."
An Israel Defense Forces (IDF) spokesman said soldiers had fired on people carrying out "terrorist activity and not on demonstrators, who were dispersed by usual means such as tear gas and according to the rules of engagement".
Announcing three days of mourning, the West Bank-based Palestinian Authority President Mahmoud Abbas said: "Today once again, the massacres against our people continue."