Fire rises during an explosion following an Israeli strike on the border tunnels between Egypt and Rafah in the southern Gaza Strip on November 21, 2012. To a backdrop of airstrikes and mounting casualties, American efforts to negotiate a cease-fire in the latest Gaza fighting between Israel and Hamas continued Wednesday. Photo by Abed Rahim Khatib / Flash 90

Palestinians seen near heavy smoke following an Israeli air strike near smuggling tunnels between Rafah and Egypt in the southern Gaza Strip on November 21, 2012. Fighting raged on both sides of Gaza's borders Wednesday despite intensified efforts across the region to thrash out a truce to end a week of violence that has cost 136 Palestinian and five Israeli lives. Photo by Abed Rahim Khatib / Flash 90

A Palestinian man reacts after an Israeli air strike near smuggling tunnels between Rafah and Egypt in the southern Gaza Strip on November 21, 2012. Fighting raged on both sides of Gaza's borders Wednesday despite intensified efforts across the region to thrash out a truce to end a week of violence that has cost 136 Palestinian and five Israeli lives. Photo by Abed Rahim Khatib / Flash 90

A Palestinian man seen walking near heavy smoke following an Israeli air strike near smuggling tunnels between Rafah and Egypt in the southern Gaza Strip on November 21, 2012. Fighting raged on both sides of Gaza's borders Wednesday despite intensified efforts across the region to thrash out a truce to end a week of violence that has cost 136 Palestinian and five Israeli lives. Photo by Abed Rahim Khatib / Flash 90

Palestinians celebrate in the streets of Gaza as Israel and the Islamist Hamas movement agreed on Wednesday to an Egyptian-sponsored ceasefire to halt an eight-day conflict November 21, 2012. Photo by Abed Rahim Khatib / Flash 90

Palestinians celebrate in the streets of Gaza as Israel and the Islamist Hamas movement agreed on Wednesday to an Egyptian-sponsored ceasefire to halt an eight-day conflict November 21, 2012. Photo by Abed Rahim Khatib / Flash 90

An explosion on a Tel Aviv passenger bus on Wednesday Nov 21 2012 left 21 people wounded, three of them seriously. Eye witnesses described a scene of panic as most onlookers were convinced that Hamas had made good on its earlier threat to resume suicide bomb attacks against Israeli civilians. Photo by Flash90

An explosion on a Tel Aviv passenger bus on Wednesday Nov 21 2012 left 21 people wounded, three of them seriously. Police commissioner Yohanan Danino said that all signs point to a terror attack. Photo by Flash90

An Israeli police man looks on at the shattered window of a public passenger bus which exploded in Tel Aviv on Wednesday Nov 21 2012 leaving 21 people wounded, three of them seriously. Police commissioner Yohanan Danino said that all signs point to a terror attack. Photo by Flash90

An Israeli police man looks on at the shattered window of a public passenger bus which exploded in Tel Aviv on Wednesday Nov 21 2012 leaving 21 people wounded, three of them seriously. Police commissioner Yohanan Danino said that all signs point to a terror attack. Photo by Flash90

An Israeli police man looks on at the shattered window of a public passenger bus which exploded in Tel Aviv on Wednesday Nov 21 2012 leaving 21 people wounded, three of them seriously. Police commissioner Yohanan Danino said that all signs point to a terror attack. Photo by Flash90

Ultra orthodox rescue personnel look on at the scene of an explosion on a Tel Aviv passenger bus on Wednesday Nov 21 2012 leaving 21 people wounded, three of them seriously. Eye witnesses described a scene of panic as most onlookers were convinced that Hamas had made good on its earlier threat to resume suicide bomb attacks against Israeli civilians. Photo by Flash90

Ultra orthodox rescue personnel look on at the scene of an explosion on a Tel Aviv passenger bus on Wednesday Nov 21 2012 leaving 21 people wounded, three of them seriously. Eye witnesses described a scene of panic as most onlookers were convinced that Hamas had made good on its earlier threat to resume suicide bomb attacks against Israeli civilians. Photo by Flash90

Natali and Alex Menkar hold their first born baby at the Assaf Harofeh Medical Center Nov 21 2012. The couple's house was ruined after being hit by a Fajr-3 Artillery Rocket. Photo by Gideon Markowicz/Flash90

Palestinian protestors confront Palestinian riot police during a demonstration against US Secretary of State Hillary Clinton's visit in the West bank city of Ramallah. November 21, 2012. Photo by Issam Rimawi/FLASH90

Palestinian protestors burn the American flag during a demonstration against US Secretary of State Hillary Clinton's visit in the West bank city of Ramallah. November 21, 2012. Photo by Issam Rimawi/FLASH90

Palestinian protestors burn the American flag during a demonstration against US Secretary of State Hillary Clinton's visit in the West bank city of Ramallah. November 21, 2012. Photo by Issam Rimawi/FLASH90

Palestinian youth throw stones towards Israeli forces at the Qalandia checkpoint, near the West Bank town of Ramallah, as they protest Israel's military operation in Gaza. November 20, 2012. Photo by Issam Rimawi/FLASH90

An Israeli soldier takes cover during clashes with Palestinians at the Qalandia checkpoint, near the West Bank town of Ramallah, as Palestinians protest Israel's military operation in Gaza. November 20, 2012. Photo by Issam Rimawi/FLASH90

Israel's Prime Minister Benjamin Netanyahu attends a press conference at the PM's office in Jerusalem, announcing a ceasfire. November 21, 2012. Photo by Miriam Alster/FLASH90

Israel's Defense Minister Ehud Barak attends a press conference at the PM's office in Jerusalem, announcing a ceasfire. November 21, 2012. Photo by Miriam Alster/FLASH90

Israel's Defense Minister Ehud Barak arrives to a press conference at PM Netanyahu's office in Jerusalem, announcing a ceasfire. November 21, 2012. Photo by Miriam Alster/FLASH90