Israeli troops shot at Palestinian protesters along the border of Syria, Lebanon and Gaza Sunday killing at least 15 people as demonstrators marked the anniversary of Israel's creation.
Witnesses and Lebanese officials say Israeli troops killed 10 Palestinians and wounded more than 50 others when the troops fired on protesters to prevent them from crossing into Israel from Lebanon.
Demonstrators in Syria also tried to break through a border fence in the Israeli-occupied Golan Heights. A Syrian official and witnesses say Israeli troops opened fire, killing four and wounding at least 45.
Elsewhere, Palestinian medics and officials say clashes at protests along the border with the Hamas-ruled Gaza Strip killed at least one person and wounded at least 60.
While outside Jerusalem, medical sources say more than 100 were injured when soldiers fired tear gas and rubber bullets to break up a group of demonstrators throwing stones.
Also in Egypt, troops fired tear gas at several hundred pro-Palestinian demonstrators outside of the Israeli embassy.
The Palestinian protests are marking what they call the "Naqba," or the "catastrophe." It describes the uprooting of Palestinian families at the time of Israel's creation in 1948.
Israeli Prime Minister Benjamin Netanyahu said in a televised address Sunday that Israel is determined to defend its borders.
The country heightened security in anticipation of unrest leading up to Sunday's protests.
Video clip: Israel - Palestinian clash
U.N. special coordinator for Lebanon Michael Williams said he deplored the loss of life. He called the violence one of the most serious incidents on the border between Israel and Lebanon since 2006.
Valerie Amos, who is U.N. Under Secretary-General for Humanitarian Affairs and Emergency Relief, visited the West Bank and East Jerusalem Sunday. She met with Palestinian President Mahmoud Abbas and Prime Minister Salam Fayyad in Ramallah, where she reaffirmed the U.N.'s commitment to the Palestinian people's right to statehood and freedom from occupation.
More than 700,000 Palestinians are estimated to have fled or have been forced to leave their homes during the war that followed Israel's declaration of statehood in 1948.
Israel, which uses the Hebrew calendar, celebrated its 63rd anniversary last Tuesday.
Some information for this report was provided by AP, AFP and Reuters.