U.N. envoy meets with Syrian president as deaths mount across country Opposition group: Six rebels die after inhaling a white gas Government and rebel forces trade blame for a major attack on a bakery that killed civilians Activists say MiG planes bombed the bakery in western Syria People had been waiting for bread for almost a week (CNN) -- With the carnage in Syria reaching unimaginable levels, U.N. peace envoy Lakhdar Brahimi met with Syria's president Monday in hopes of making headway in ending the country's civil war. But a lack of details after the meeting suggests that the 21-month-old crisis might still be far from over. "We have exchanged opinions about the possible steps that can be taken in the future," Brahimi told reporters after meeting with President Bashar al-Assad. The president spoke about his view regarding this situation. I also talked about the meetings I had abroad in several cities with various officials in the region and outside of the region. I also talked about what steps which I see appropriate to be taken to help the Syrian people to get out of this crisis," he said. The situation in Syria remains worrying. We hope that all parties embrace the solution which the Syrian people want and aspire to have. Brahimi has visited Damascus several times as the joint U.N.-Arab League special envoy to Syria. In October, he brokered a cease-fire deal between the government and rebels. But that plan disintegrated within hours when heavy fighting erupted once again. Opposition activists say more than 4,000 civilians have been killed in the past two months. The bloodshed continued Monday, when at least 15 people were killed across the country, the opposition Local Coordination Committees of Syria said. Dissidents in the embattled city of Homs said six rebel fighters died Sunday night after inhaling a white gas that had no smell, according to Rami Abdulrahman, director of the opposition Syrian Observatory for Human Rights. "Gas was released and spread in the area after members of the regime forces threw canister bombs," Abdulrahman said Monday. ..." The activists said that everyone who (inhaled) the gas felt severe headaches and some had cases of epilepsy. The observatory called for the International Red Cross to intervene and investigate the case. CNN cannot independently confirm reports of the attack. The latest reports of violence come a day after more than 100 people who had been without bread for days were killed when warplanes bombed a bakery in the western village of Halfaya, opposition activists said Sunday. An activist who oversaw the burial of many bodies said at least 109 people died. Hassan Al-Rajb told CNN that 69 people were identified and buried, while 15 unidentified bodies were laid to rest. The hospitals could not handle all the wounded, he said. There were dozens of dead thrown in the street. The residents were shocked and in a state of fear. It was chaotic," opposition activist Mahmoud Alawy said. Many bodies had limbs apparently blown off, and others lay bloody in the streets and in rubble strewn over a sidewalk. Uniformed rebels from the Free Syrian Army and civilians scrambled to pull survivors out of the carnage. But the state-run Syrian Arab News Agency said that "armed terrorist groups" attacked Halfaya, shot footage of the incident and blamed the government for the attack. Halfaya had lacked the ingredients for bread for about a week until an aid group delivered provisions Saturday, Alawy said. Hundreds of people lined up at the bakery Sunday. Alawy said the government has been targeting large gatherings of people with artillery shells in the recent days since the Free Syrian Army liberated the town from Syrian forces. Many Syrians face shortages of food and other needs as winter weather sets in. The United Nations estimates that more than 2.5 million people need humanitarian assistance. Syria firing more Scud missiles, NATO says CNN's Salma Abdelaziz and Samira Said contributed to this report.