Nakba Day commemorates the destruction of hundreds of villages in historical Palestine and the expulsion of hundreds of thousands of people from their land to make way for the new state of Israel in 1948.
Thousands of Palestinians marched in the occupied West Bank and the Gaza Strip to commemorate Nakba Day on Monday.
Nakba, or "day of catastrophe", is officially marked each year on May 15 to commemorate the displacement of some 750,000 Palestinians who were forced from their homes during the war that led to the creation of Israel in 1948.
On Monday, Chief Palestinian negotiator, Saeb Erekat, demanded an apology from Israel for the expulsion of thousands of Palestinians from their land.
"Our nation marking 69 years of the Nakba, our national catastrophe, is symbolised in our exile and the systematic denial of our rights," said Erekat in a statement.
Erekat also called on Britain to apologise for the Balfour declaration, which in 1917 pledged a Jewish homeland in then-British controlled Palestine.
Palestinians annually commemorate the Nakba, which forced most of those expelled into refugee camps that still exist in the West Bank, Gaza, Jordan, Syria and Lebanon.
"We call upon the Israeli government to open all of its 1948 archives and show their own nation the truth of what was done to our people, including its ethnic cleansing policies and the policy of shooting to kill Palestinians that attempted to return home," said Erekat.
This year the day coincides with a hunger strike being held by more than 1,000 Palestinian prisoners in Israeli jails.
The strike, which began on April 17, was being led by Marwan Barghouti, the most high-profile Palestinian in Israeli detention.
Barghouti called on Palestinians to engage in civil disobedience on Nakba Day.