BEIRUT, Lebanon — Violence surged in Syria on Tuesday as activists reported that at least 34 people had been killed in several towns and cities across the country, including six soldiers who had defected and three members of the security forces.  The bloodshed, a marked increase even for an uprising that has proved to be among the most violent in the Arab world, came despite the presence of monitors from the Arab League. The deaths underlined the grim trajectory of a conflict that shows little likelihood of a diplomatic breakthrough.  The monitors were sent last month after Syria signed an agreement calling for an end to a government crackdown against protesters, the withdrawal of all military vehicles from the streets and the release of all political prisoners.  In the northern province of Idlib, near the Turkish border, a roadside bomb struck a minibus, killing at least eight passengers, according to the opposition Local Coordination Committees. Members of the activist group said the improvised explosive device was planted by Syrian security forces loyal to the government of President Bashar al-Assad. It was not possible to independently confirm their report, and both sides in the conflict routinely blame the other.  It was the second such attack in the region in two days, and conflicting accounts of events and the number of casualties were offered by activists and the Syrian state news agency. An activist from the area who gave his name as Abu Moayed said the bus was hit by two rocket-propelled grenades that were fired by men driving a Peugeot 504, a model often used by the security forces. In a different account, the Syrian state news agency said four people were killed and five were wounded in Tuesday’s attack. It reported that the explosion, which it said was the work of terrorists, struck the bus on the road linking the cities of Saraqib and Idlib in the province of Idlib. The news agency, SANA, quoted a police official in the area as saying the bomb was planted on the right side of the road and was detonated by remote control.  The Local Coordination Committees also said Syrian security forces attacked several neighborhoods in the besieged city of Homs in central Syria, killing at least 19 people. The city, near the border with Lebanon, has been the most embattled in Syria.  Avaaz, a human rights group, said the shelling of the neighborhoods of Khaldiya and Bayada was in reaction to a series of attacks by insurgents against several checkpoints on Tuesday morning.  A video posted on YouTube showed a tank driving on what activists said was Cairo Street in the neighborhood of Bayada and firing on unidentified targets.  A resident from Homs reached through Skype called the situation “unbearable,” saying the roads had checkpoints and barricades every few miles, while snipers were visible on rooftops of buildings held by pro-government forces.  The town of Zabadani, also near the border with Lebanon, was under siege for the fifth consecutive day, with the water shut off and communication lines down in several areas, according to activists and residents there reached by cellphone.  “The situation is so bad in the western part of the town, more than half of the residents left the area,” said Farres Mohammad, a resident of Zabadani. “We are under siege. The army is not letting anything pass through, not even the air.”  The Local Committees also said the bodies of three soldiers who had defected from the army were discovered in a cemetery in the town of Ariha in Idlib. A video posted on YouTube showed what appeared to be the three soldiers wearing civilian clothes as they lay motionless on the ground. One of them had his legs and arms tied. The group said the soldiers had been hiding in the cemetery.  On Monday, the Syrian Free Army, a group of defected soldiers whose leader is based in Turkey, called on the United Nations to invoke its charter, which the group says gives the United Nations the right to take military action against Syria to end the violence.  Qatar’s emir, Sheik Hamad bin Khalifa al-Thani, was quoted on Saturday as saying that Arab countries should send their troops to Syria to end the authorities’ brutal crackdown on protesters and help stop the violence, which has persisted despite the arrival of the Arab League observers. His statement was the first of its kind by an Arab leader.  Syria’s Foreign Ministry said in a statement on Tuesday that it “absolutely rejects” any plans to send Arab troops into the country. “The Syrian people reject any foreign intervention in its affairs, under any title, and would confront any attempt to infringe upon Syria’s sovereignty and the integrity of its territories,” the statement said.  Syria says that armed foreign groups are behind the violence, not pro-democracy protesters, and the government says that at least 2,000 police officers and soldiers have been killed since the unrest broke out last year.  The United Nations said that at least 400 people had been killed in the past three weeks in Syria, adding to the toll of 5,000 people killed from mid-March to December. United Nations Security Council members renewed discussions on Tuesday on a revised draft proposal by Russia that addressed the Syrian conflict. The United States ambassador, Susan E. Rice, described the talks as “stuck.”  Another Western diplomat, speaking anonymously because of the delicate nature of the talks, accused the Russians of dragging out the negotiations to buy time for the Syrian government and said the new draft included a whole “catalog” of accusations against the opposition.  The Russian mission spokesman, Anton Uspensky, said work on the draft was continuing. “We have taken into consideration all the comments, and they are being discussed,” he said.  Hwaida Saad and an employee of The New York Times contributed reporting from Beirut, and Neil MacFarquhar from the United Nations.
The United Nations Security Council renewed discussions about the Syrian conflict but appeared no closer to a diplomatic breakthrough.