Two car bombs shook the Damascus region on Tuesday, a watchdog said, a day after nearly 250 people died in fighting and bombings in Syria's worst violence since last month's failed ceasefire bid.

One car bomb exploded before dawn in the city of Mudamiya near the capital, causing injuries and significant damage, the Syrian Observatory for Human Rights said.

Egyptian Foreign Minister Mohammed Kamel Amr arrived in Beirut on Tuesday for a two-day visit to meet with senior Lebanese officials and stress his country's support to the resumption of the national dialogue among the political foes.

He kicked off his visit by meeting with Lebanese Forces leader Samir Geagea in Maarab and later Speaker Nabih Berri and Phalange Party leader Amin Gemayel.

An Israeli military vehicle on the occupied Golan Heights was hit by gunfire from neighboring Syria on Monday, the Israeli army said.

"A military vehicle traveling in the Golan was hit by gunfire from Syria. Apparently they were stray bullets, and there were no injuries" to those aboard the vehicle, a military spokesman told Agence France Presse.

Syria's main opposition bloc, under U.S. pressure to reshape into a widely representative government-in-exile, agreed on Monday to broaden its structure to accommodate 13 other groups, a spokesman said.

The decision by the Syrian National Council came on the second day of a four-day meeting of opposition groups in the Qatari capital Doha aimed at forging a more united front against Syrian President Bashar Assad's regime.

Syrian rebels launched a devastating car bomb attack Monday that killed 50 pro-regime fighters, a watchdog said, as air strikes pounded rebel positions and the opposition met for talks on an overhaul.

The suicide car bomb attack on a military post in the central province of Hama struck early Monday, killing at least 50 government troops and loyalist militiamen, the Syrian Observatory for Human Rights said.

More than 30 people were killed in a 24-hour period in a Palestinian refugee camp south of the Syrian capital Damascus amid fierce clashes between the army and rebels, Palestinian sources said on Monday.

Seven people were killed Monday when a mortar landed on a mini-bus traveling along the western edge of the Yarmouk Palestinian camp, according to Palestinian sources and Syrian state television.

Syria's former prime minister Riad Hijab met Turkish Foreign Minister Ahmet Davutoglu on Monday to discuss efforts to restructure the fragmented Syrian opposition, a diplomatic source told Agence France Presse.

"The ways to address the Syrian crisis and a reorganization among the Syrian opposition ranks were discussed," in the meeting, the source said.

Russia's Foreign Minister Sergei Lavrov on Monday accused countries which support Syrian rebels of encouraging them to fight rather than pressuring them to negotiate an end to Syria's civil war.

Russia, one of the Syrian regime's most influential foreign allies, held no sway over the rebels, Lavrov said at a news conference in Cairo with his Egyptian counterpart Mohammed Kamel Amr.

A Lebanese man was killed after a shell hit a Syrian town that borders the Hermel district in Lebanon's northeast, the National News Agency reported on Monday.

Bassel Ahmed al-Haq, 22, died on Sunday night when the shell hit an area near his parents' house in the Syrian town of al-Sefsaf that borders the Lebanese village of Hawsh al-Sayyed Ali in Hermel.

Tokyo will host an international conference later this month aimed at increasing pressure on the regime of Syrian President Bashar Assad, Japanese officials said Monday.

"The meeting is aimed at broadening the range of countries taking part in sanctions and enhancing the effectiveness of pressure on the Syrian government," Chief Cabinet Secretary Osamu Fujimura said.