AMMAN/DAMASCUS (Reuters/AFP) - Syrian forces shot dead at least 28 at rallies after Juma prayers, activists said, and refugees described gunbattles between mutinous soldiers and other troops in recent days. The Syrian army swept into the northwestern border town of Jisr al-Shughour and began to arrest "armed opponents," state television said. Thousands of civilians have fled the town into Turkey, fearing the security forces' revenge for incidents in which 120 troops were reported killed this week. State television said that some 35 km (20 miles) away, well-armed "terrorist groups" burned police buildings and killed members of the security forces in the town of Maaret al-Nouman. The nature of the alleged "terrorist groups" was unclear. Authorities have repeatedly tried to portray anti-government protesters as armed and violent. But protesters, refugees in Turkey and rights activists said some soldiers in the northwest had refused to shoot at protesters and fighting had broken out between loyalist and mutinous forces this week. Meanwhile, Turkey accused the regime of atrocities and the US slammed the "slaughter of innocent lives." "Army units have started their mission to control Jisr al-Shughur and neighbouring villages and arrest the armed gangs," state television said, adding that the raid on the northwestern town came "at the request of residents." One witness told AFP that "military forces bombarded the villages around Jisr al-Shughur in their advance on the town." "Soldiers torched wheat fields in the village of Al-Ziyara," 15 kilometres (nine miles) southeast of Jisr al-Shughur, he said. Rights activists said most of the 50,000 inhabitants of Jisr al-Shughur had fled - many to neighbouring Turkey - when tanks and troops began converging on the town midweek and that it was now largely deserted. State television blamed "armed terrorist gangs" on Wednesday as it ran images of "massacres" in Jisr al-Shughur which it said had resulted in the deaths of 120 police and troops on Monday. But opposition activists said the deaths resulted from a mutiny by troops who refused orders to crack down on protesters. It was not possible to independently verify the version of events as foreign journalists are banned from reporting in Syria. Protesters, meanwhile, poured on to the streets of main towns and cities Friday after Juma prayers, many chanting slogans against President Bashar al-Assad and in support of Jisr al-Shughur residents. Security forces shot dead at least 22 anti-regime protesters, including 11 in the northwest, rights activists said. In the town of Maaret al-Numan in Idlib province, security forces fired on a large crowd and killed at least 11 people, the activists said. State television reported that "intense fire by groups of armed terrorists on a security headquarters caused dead and wounded among the police and security forces" in the town. Six people were also killed in the port city of Latakia, said Rami Abdel Rahman, head of the London-based Syrian Observatory for Human Rights. He said another two were killed in the Bosra al-Harir area of southern Daraa province, an epicentre of pro-democracy protests that have shaken Syria since mid-March. State television said "armed men" fired at security forces in Bosra al-Harir, killing a security force member and a civilian. Activists said earlier that three civilians were killed in the Qabun district of Damascus. More than 8,000 protesters marched through three Kurdish towns in the north to demand political reform and in solidarity with Jisr al-Shughur, said another activist, Hassan Berro. The marches took place at Ras al-Ain, on the border with Turkey, and in Qamishli and Amuda. The Syrian Observatory said other protests were held and gunshots heard in the city of Homs, north of Damascus. Security forces kept away as a crowd of more than 7,000 converged on Al-Assi Square, in the city of Hama, further north, where at least 60 civilians were killed on June 3, the group said, citing local residents. Protests were also reported in Dael, a town in Daraa province, and thousands gathered in the capital's Midan district as well as the suburbs of Harasta and Barzeh. Syria's opposition had called for the renewed protests under the slogan "Friday of the Tribes." More than 1,200 civilians, including dozens of children, have been killed in a government crackdown during the past three months, rights groups say. Damascus blames the unrest on "armed terrorist gangs" backed by Islamists and foreign agitators. Assad has come under fire from Turkey's Prime Minister Recep Tayyip Erdogan, a personal friend. "Unfortunately they do not behave humanely," Erdogan said in a television interview late Thursday carried by Anatolia news agency, describing the treatment of the bodies of women slain by the security forces as an "atrocity." "I talked to (Assad) four or five days ago," said Erdogan. "But they underestimate the situation." Erdogan said the brutal crackdown was "unacceptable" and would "necessarily" lead the UN Security Council to step in. It was Ankara's harshest reaction yet to the Syrian turmoil, which has forced more than 3,000 people to seek refuge across the border in Turkey. US Defence Secretary Robert Gates piled pressure on Assad on Friday, saying his very legitimacy was on the line. "The slaughter of innocent lives in Syria should be a problem and concern for everybody," Gates said in Brussels. "And whether Assad still has the legitimacy to govern in his own country after this kind of a slaughter I think is a question everybody has to consider." The United States and its allies are looking to increase pressure on Syrian President Bashar al-Assad to step down or allow for a peaceful transition, a State Department spokesman said Friday. "(Assad) has refused to reform, refused even to make any gesture towards reform other than empty rhetoric," Mark Toner said