A masked Palestinian youth throws a fire bomb towards Israeli forces during clashes following Friday prayer in Arab East Jerusalem on May 13, 2011. Israeli police flooded the streets, fearing violence, as Palestinians began marking the anniversary of what they call the "Nakba," or catastrophe, that befell them following Israel's establishment in 1948. #

A Palestinian man holding a Palestinian flag looks at fellow demonstrators gathering during clashes with Israeli soldiers in Maroun al-Rass near the Israeli border in South Lebanon on May 15, 2011. #

Druze spectators stand on a roof as they watch Syrian protesters making their way back to Syria. The protestors had crossed into Israel during a demonstration marking the annivesary of "Nakba" on the border between Syria and Israel in the village of Majdal Shams, Golan Heights, on May 15, 2011. #

Arab demonstrators marking the anniversary of the 1948 mass displacement of Palestinians run away from an Israeli military vehicle as they try to approach the village of Majdal Shams in the Golan Heights between Syria and Israel on Sunday, May 15, 2011. #

Lebanese soldiers take a position on the Lebanese-Israeli border as Palestinian refugees in Lebanon (not seen) gather for a protest, as seen from the Israeli village of Avivim on May 15, 2011. #

A masked Palestinian demonstrator walks past a graffiti message on Israel's controversial separation barrier during clashes with Israeli soldiers in the West Bank village of Anata on May 15, 2011. Palestinians were marking the anniversary of the 1948 creation of Israel as "Nakba" or catastrophe. #

Palestinian protesters in the east Jerusalem neighborhood of Issawiyeh, Sunday, May 15, 2011, carry a couch to block the road during clashes with Israeli troops (not seen) following a demonstration to mark the 63rd anniversary of "Nakba," Arabic for catastrophe -- the term used to mark the events leading to Israel's founding in 1948. #

Palestinian refugee Mahmoud Amer, 75, shows the keys of his home in the village of Mansi in what is now Israel on May 15, 2011, in the West Bank refugee camp of Jenin. #

A plainclothes Israeli police officer detains a Palestinian protester following a demonstration to mark the 63rd anniversary of "Nakba," Arabic for catastrophe, in the Qalandiya checkpoint between Ramallah and Jerusalem, on Sunday, May 15, 2011. #

A Hamas security officer uses a club to prevent protesters from reaching Erez Crossing during a march heading towards the border with Israel in the northern Gaza Strip on Sunday, May 15, 2011. #

An undercover Israeli policeman dressed as a Palestinian woman opens a car door after detaining a Palestinian protester during clashes in Shuafat refugee camp in the West Bank near Jerusalem on May 15, 2011. #

The body of a Syrian protester is carried near the border fence between Syria and Israel, close to the northern Druze village of Majdal Shams in the Golan Heights, on May 15, 2011. #

An Israeli policeman carries a Palestinian boy after removing him from a burning house during clashes in the East Jerusalem neighborhood of Issawiya on May 15, 2011. #

Palestinians carry the coffins of people who were shot dead yesterday by Israeli soldiers during clashes at the village of Majdal Shams in the Golan Heights, during a funeral in al-Yarmouk camp near Damascus, Syria, on May 16, 2011. #