More violence, protests in Syria as U.S., Turkish leaders discuss aiding opposition NEW: 11 civilians die in the "Morek Massacre," 5 by firing squad, an opposition group says NEW: At least 58 people are killed across Syria on Sunday, the same group claims Obama and Erdogan talk about providing medical supplies to the Syrian opposition Russia's president pledges to assist U.N. special envoy Kofi Annan's mission in Syria (CNN) -- Sunday was marked by a slew of anti-regime protesters and yet more violence targeting dissenters in Syria, while outside the embattled country the leaders of the United States and Turkey discussed ways to aid the opposition. The bloodshed includes what the Local Coordination Committee of Syria, a network of opposition groups, is calling the "Morek Massacre." The group claimed that 11 civilians calling for the regime's ouster were murdered, among them five "executed by firing squad." In total, the LCC reported that at least 58 died across the Middle Eastern nation Sunday, including 16 in the province of Homs, 14 in Hama (where the town of Morek is located), 10 in Idlib, 10 in the suburbs of Damascus, five in Daraa and three in Aleppo. The same group also stated that such violence did not prevent demonstrations in upwards of 18 locales around Syria -- many of which it described as "massive," and documented with YouTube videos. CNN cannot independently confirm reports of protests, casualties or attacks in Syria, because the government severely restricts access by international journalists. Meanwhile, U.S. President Barack Obama and Turkish Prime Minister Recep Tayyip Erdogan met Sunday to discuss how to aid the Syrian opposition and exert pressure on Syrian President Bashar al-Assad's regime to end its brutal crackdown on civilians. The meeting, which took place in Seoul, South Korea, where the leaders will attend a nuclear summit this week, was aimed at "syncing up" with Turkey -- a former Syrian ally -- before Istanbul hosts the next "Friends of Syria" meeting on April 1, a senior Obama administration official said. Obama and Erdogan expect the upcoming conference to enhance ways to provide "non-lethal" aid to the opponents of the Syrian regime, such as medical supplies and communications equipment, said Ben Rhodes, a U.S. deputy national security adviser. "We cannot be spectators," Erdogan said Sunday after the meeting in South Korea. Erdogan said 17,000 refugees have fled from Syria to Turkey. Obama said he and Erdogan "are very much in agreement that there should be a process" to transition to a "legitimate government," in contrast to al-Assad's current government. He also pledged to keep pursuing humanitarian aid as reports of carnage at the hands of the the Syrian regime mount daily. A key political opposition body in Syria said Sunday that in a post-Assad era, the Syrian state would be based on "equality," regardless of ethnicity, religious beliefs or political affiliation. In a new charter, the Muslim Brotherhood vowed "to protect all rights, to dispel fears, inspire trust and confidence." Some analysts have expressed concern about what the Sunni-dominated Muslim Brotherhood might do if al-Assad's Alawite-dominated regime falls. In its announcement Sunday, the group said it is committed to "democracy, pluralism, equality and human rights," as well as rejecting and fighting terrorism. The group also said every citizen should have equal rights to run for office. Sunday's announcement comes after a top defector from the Syrian military said armed rebel groups have aligned under the leadership of the Free Syrian Army. These differing accounts were evident again Sunday of the southern city of Nawaa. The opposition Syrian Observatory for Human Rights said five defected soldiers and three members of al-Assad's security forces were killed in the fighting. The state-run Syrian Arab News Agency said "six of the most dangerous wanted terrorists" were killed in clashes as authorities "stormed a den of terrorists." Two "competent authorities" were also killed, the government news agency said. On Sunday, Kofi Annan -- a former U.N. secretary-general who is now serving as a special envoy with that world body and the Arab League -- was in Moscow to seek help from longtime al-Assad ally Russia in helping bring about a cease-fire in Syria. Russia's president praised Annan's efforts and pledged to offer assistance, the state-run RIA Novosti news agency reported. Perhaps, it's Syria's last chance to avoid a bloody civil war. We are very hopeful that your work will have a positive result," President Dmitry Medvedev told Annan, according to the news agency. Russia and China have blocked U.N. Security Council attempts to pass resolutions condemning the al-Assad regime. The two countries say they want the violence to stop, but would not blame the bloodshed squarely on the regime.