Ki-moon urged all sides to show the "utmost responsibility"

The body of a demonstrator is carried by fellow protesters in the southern Lebanese village of Marun al-Ras. Israeli gunfire killed 12 people and wounded hundreds as Palestinians marched on Israel's borders with Lebanon, Syria and Gaza in a mass show of mourning over the creation of the Jewish state. Tensions along the Israeli-Syrian frontier spiralled as thousands of protesters from Syria tried to force their way onto the Israeli-occupied Golan Heights, prompting the army to open fire in one of the worst incidents of violence there since a 1974 truce accord.
Syria lashed out at Israel for the bloodshed, warning it would bear full responsibility for its "criminal" actions, while Lebanon filed a complaint to the United Nations, urging it "to make the Jewish state halt its aggression and provocation," Lebanon's official NNA news agency reported.
UN Secretary General Ban Ki-moon expressed deep concern over the violence and urged all sides to show the "utmost responsibility" to ward off new hostilities, a UN spokesman said.
"The secretary general is deeply concerned that a significant number of people have been killed or injured. He calls on all concerned to show restraint and refrain from provocations so as to prevent escalation of tensions," his spokesman Martin Nesirky said.
Ban called for "calm throughout the region and utmost responsibility from all concerned."
Prime Minister Benjamin Netanyahu vowed Israel would protect its borders faced with those who sought its destruction.
"Their struggle is not over the 1967 borders, but it questions the very existence of Israel, which they describe as a catastrophe which must be resolved," he said in a televised address.
"We are determined to defend our borders and our sovereignty."
A Druze doctor from Majdal Shams who rushed to the scene told AFP he saw at least two bodies, with local paramedics confirming the same toll, saying one had been shot in the head, and the second in the chest.
They also treated 20 people for light to moderate injuries.

Along the Lebanese border, Israeli gunfire killed 10 people and wounded 110 as thousands of mainly Palestinian refugees demonstrated along the tense frontier, medical sources said.
And along Gaza's northern border with Israel, 125 people were injured, five of them seriously, when troops opened fired as more than 1,000 Palestinians marched on the Erez crossing.
At least half of the wounded were minors, medics said.
The Israeli army issued a statement saying "hundreds of Syrian rioters" had crossed onto the Israeli side, and in response troops had "fired selectively" towards them, injuring an unspecified number.
Protesters in southern Lebanon had tried to cross the border into Israel, the statement added, saying troops had fired warning shots towards them.
Three army officers and 10 soldiers had been injured during the two incidents, it said, blaming Damascus and Beirut for the violence.
Elsewhere, at least 29 others were injured in clashes across annexed east Jerusalem and in the West Bank.
Israeli troops also shot dead a Palestinian in an area east of Gaza City but medics said the incident was not related to the nakba protests.
In southern Gaza, more than 5,000 demonstrators also held a mass rally in the southern city of Rafah, which lies on the border with Egypt, an AFP correspondent said.
They waved Palestinian flags and held up huge replica wooden keys to homes they fled or were expelled from during the Arab-Israeli war which accompanied the creation of the Jewish state.

Since Friday, Palestinians and Arab Israelis staged a series of events in the run-up to Sunday's anniversary, marking the anniversary of Israel's creation in 1948, in an event referred to in Arabic as the "nakba" or "catastrophe."
In the southern city of Hebron, 12 people were hit by rubber bullets fired by Israeli troops as an estimated 2,000 demonstrators held a protest, medical and security sources said.
And 17 people were hospitalised in Ramallah after being hit by rubber bullets during heavy clashes close to the Qalandiya crossing near annexed east Jerusalem, as thousands gathered for a protest, medical sources said.
Police arrested 36 people after a day of clashes in the east Jerusalem, while in Tel Aviv, police were investigating after a truck driven by a 22-year-old Arab Israeli ploughed into a bus and four cars, killing one and injuring another five.
The driver blamed the incident on a burst tyre, but police said they were investigating whether the driver had been acting on nationalist motives.
In Jordan, six people were injured as police tried to stop 200 students from marching on the border, while in Turkey about 100 demonstrators held a protest outside the Israeli consulate in Istanbul, AFP correspondents said.
In Egypt, protesters clashed with security forces outside the Israeli embassy in Cairo, as army troops fired tear gas and shots into the air to disperse a hundreds-strong crowd. At least 24 people were injured in the clashes, according to the health ministry, quoted by the official MENA news agency.
The protests began on Friday and quickly turned deadly when an east Jerusalem teenager was shot in the stomach during clashes in Silwan. He later died, with his family blaming the death on a Jewish settler.
More than 760,000 Palestinians -- estimated today to number 4.8 million with their descendants -- were pushed into exile or driven out of their homes in the conflict that accompanied the Jewish state's foundation.
Figures from the UN agency for Palestinian refugees show there are one million refugees in the Gaza Strip, 750,000 in the West Bank, two million in Jordan, 475,000 in Syria and 400,000 in Lebanon.