(CNN) -- Already devastated by weeks of constant attacks this year, the Syrian city of Homs faced new terror Sunday as pro-regime forces executed 10 young men in the dissident stronghold, opposition activists said.
Forces loyal to President Bashar al-Assad stormed the Shammas neighborhood of Homs and gathered 350 young men in the square of a mosque, said the Syrian National Council, an umbrella opposition group.
"The military began calling the residents from the mosques surrounding the Shammas neighborhood that all young men need to come down to the streets with their hands behind their heads," the SNC said.
Another opposition group, the Syrian Observatory for Human Rights, said three children were killed when regime forces fired on a minibus carrying residents fleeing the Shammas neighborhood.
But Syria, on state-run TV, blamed "terrorists" for that attack, saying three people, including two children, were killed on the bus.
At least 110 people were killed in violence across the country Sunday, the opposition Local Coordination Committees of Syria said. They included 45 in Damascus and its suburbs, many of them members of the Free Syrian Army. Twenty-six of the deaths were in Homs and 20 were in Daraa, the LCC said.
Meanwhile, some opposition activists worked to distance themselves from images shown on YouTube. The latest one appears to show rebels in control of a government communications building in El Bab, part of Aleppo province, throwing the bodies of government fighters off a roof.
"We strongly condemn this heinous act," said Abdul Hafiz Abdul Rahman, an activist with the Syrian human rights organization MAF. He said when he saw the video, "I felt that part of me died, and now I'm worried about the revolution." He also cited a video posted to YouTube last month in which someone identified as a Syrian lieutenant appeared to be executed by rebels. "True, we are in a state of war, but if we do such acts like this ... then we are becoming the very entity that we are revolting against."
Such videos bolster claims by the Syrian regime that it is battling armed "terrorist" gangs.
Several cities were under attack by government forces Sunday, including Rastan, which was seeing "very intense shelling," according to the opposition LCC.
"Residents are appealing for intervention to break the siege of the disaster-stricken city, which has no access to any of life's essentials including bread, water, baby formula or electricity," the LCC said.
An activist in Rastan posted a message on Skype saying, "The shelling is continuing for hours now. There is massive destruction as well as many people killed and injured. We call for help to break the siege around the city. There is no running water or electricity. There is lack of food and baby formula. The only automated bakery was shelled so we have lack of bread as well."
Regime forces also shelled the commercial metropolis of Aleppo and the area of Daraa, where anti-government protests began in March 2011, the LCC said.
In Aleppo, fierce fighting raged again Sunday between regime and rebel fighters, opposition activists said.
The regime claimed progress in its battle against "terrorists" in the Aleppo area.
"The special authorities answer(ed) the plea of the residents of the Sufeira neighborhood in Aleppo and clashed with the terrorists, destroying their five vehicles and killing a dozen of these terrorists," Syrian state-run TV reported.
The state-run Syrian Arab News Agency reported that North Korea had expressed its support for the regime. North Korean leader Kim Jong Un and Foreign Minister Pak Ui Chun "described the U.S. and its Arab agents' policies against Syria as 'state terrorism,'" the report said.
On Saturday, the government announced the swearing in of a new prime minister, Dr. Wael al-Halqi. SANA said al-Halqi is a former chief of Syria's doctors and was the country's minister of health.
The SANA report made no mention of former Prime Minister Riyad Hijab, who resigned Monday, citing the "killing and terrorist regime." His spokesman said Hijab had no choice but to take the job because the regime would have killed him if he had declined.
Meanwhile, in neighboring Lebanon, a military court charged two Syrian army officers Saturday with attempting to form an armed group to spread sectarian violence through plotting political and religious assassinations, the state-run National News Agency reported.
The court said Syria's Brig. Gen. Ali Mamlouk, the newly appointed head of the national security bureau, and a colonel known only as Adnan provided improvised explosive devices to Lebanese politician Michel Samaha, who faces the same charges.
In neighboring Turkey on Sunday, Emine Erdogan, wife of Prime Minster Recep Tayyip Erdogan, spoke to the country's Saban newspaper about her counterpart in Syria, al-Assad's wife, Asma.
The two families have been close for years. Erdogan said she expected Asma al-Assad would have left for England with the children during the uprising.
"I wish she had called. I wish she had called then, at the beginning," said Emine Erdogan. "... If she had called, I would have told her, 'Come to Turkey with your children. Let us give you protection.' Believe me, I would want very much if she would have come and lived here with her children."
Though the Syrian civil war rages on with no end in sight, U.S. Secretary of State Hillary Clinton said Saturday the United States would start to develop contingency plans with its Turkish allies in the event that the embattled Syrian regime collapses.
Her announcement in Istanbul came 17 months into an escalating crisis that has claimed more than 17,000 lives and forced an estimated 150,000 refugees to flee into neighboring nations, including Turkey, which is hosting 50,000 people.
"There is a very clear understanding about the need to end this conflict quickly, but not doing it in a way that produces even more deaths, injuries and destruction," Clinton said after talks with her Turkish counterpart, Foreign Minister Ahmet Davutoglu.
Arab League foreign ministers were scheduled to meet in Saudi Arabia on Sunday, but the meeting was postponed, Saudi official media reported.
CNN's Saad Abedine, Holly Yan, Ivan Watson, and Josh Levs contributed to this report.