A Palestinian boy holds a torch during a rally in the West Bank city of Tubas on May 14, 2013, to mark Nakba Day on May 15, the annual day of commemoration of the displacement of Palestinians after the establishment of the state of Israel in 1948. (Xinhua/Ayman Nobani)

A Palestinian boy holds a torch during a rally in the West Bank city of Tubas on May 14, 2013, to mark Nakba Day on May 15, the annual day of commemoration of the displacement of Palestinians after the establishment of the state of Israel in 1948. (Xinhua/Ayman Nobani)

Palestinian boys holding torches take part in a rally in the West Bank city of Nablus on May 14, 2013, to mark Nakba Day on May 15, the annual day of commemoration of the displacement of Palestinians after the establishment of the state of Israel in 1948. (Xinhua/Nidal Eshtayeh)

Palestinian boys holding torches take part in a rally in the West Bank city of Nablus on May 14, 2013, to mark Nakba Day on May 15, the annual day of commemoration of the displacement of Palestinians after the establishment of the state of Israel in 1948. (Xinhua/Nidal Eshtayeh)

Abu Hafez and his wife show the keys of their former house they displaced since 1948, in Al-Jalazoun Refugee camp near Ramallah in the West Bank on May 14, 2013. Palestinians are preparing for Nakba Day on May 15, marking thousands of Palestinians that were forced to leave their homes during the Arab-Israeli war in 1948. (Xinhua/Fadi Arouri)

Abu Hafez, a 68-year-old Palestinian, holds the keys of the former house displaced since 1948, in Al-Jalazoun Refugee camp near Ramallah in the West Bank on May 14, 2013. Palestinians are preparing for Nakba Day on May 15, marking thousands of Palestinians that were forced to leave their homes during the Arab-Israeli war in 1948. (Xinhua/Fadi Arouri)

Abu Hafez, a 68-year-old Palestinian, holds the keys of the former house displaced since 1948, in Al-Jalazoun Refugee camp near Ramallah in the West Bank on May 14, 2013. Palestinians are preparing for Nakba Day on May 15, marking thousands of Palestinians that were forced to leave their homes during the Arab-Israeli war in 1948. (Xinhua/Fadi Arouri)