DAMASCUS (AFP) - Syrian security forces rounded up thousands of men as they went house to house in a bid to crush an anti-regime protest movement in the coastal city of Banias on Monday, as shots rang out in a Damascus suburb surrounded by troops, activists said. Protests organisers meanwhile called for a day of solidarity Tuesday with "prisoners of conscience" held in Syrian jails, according to a statement posted on the Syrian Revolution 2011 Facebook page. Rami Abdul Rahman, head of the London-based Syrian Observatory for Human Rights, said water, electricity and telephone lines have been cut off in Banias, on Syria's northwest Mediterranean coast. "There were house-to-house raids overnight and it continued on Monday morning," Abdul Rahman said, adding that the men were being rounded up for questioning in a stadium based on lists of names. "Thousands of men, including youths, have been rounded up by the army and security forces... to be interrogated and they are being beaten. More than 400 are still being held," the activist said. He denounced the authorities for using brutal force to crush the protests, telling AFP: "The military solution is useless in Syria. Things will only be solved when a democratic society emerges." "Residents hoped that the army would arrest regime supporters who have terrorised Banias but instead the army arrested unarmed residents," he said. Among those detained were protest leaders and doctors at a hospital which was encircled by the military, the Syrian Observatory said in a statement on Sunday. The military said six soldiers, including three officers, were killed in clashes Sunday as the army pursued "armed terrorist groups" in Banias, the Homs and the countryside around the southern town of Daraa - three protest hubs. Tanks rumbled into several districts of the central industrial city of Homs and deployed along the corniche in Banias overnight Saturday-Sunday, according to activists. "Banias is cut off from the outside world," one activist said. Owners of Internet software shops have also been arrested, he said, although detainees aged over 40 had been released. Hundreds of women have taken to the streets of Banias since early Monday to demand the release of men arrested by security forces and some even charged checkpoints to vent their anger, activists said. Meanwhile gunfire broke out in the western Damascus suburb of Muadamiya in the morning and telephone lines were cut, an activist said. "Troops and security forces are circling Muadamiya," said the activist. A witness confirmed the report, saying the main road to the Damascus suburb had been sealed off. The source of the gunfire could not immediately be determined. Despite the heavy-handed repression, the Syrian Revolution 2011, a Facebook group that has been a motor of the protests, said "demonstrations will continue every day." It also called for "a Tuesday of solidarity with prisoners of conscience held in the jails of the criminal Syrian regime." Embattled President Bashar al-Assad, quoted on Monday in Al-Watan newspaper which is close to the government, vowed to press ahead with reforms and forecast the political crisis in Syria was nearing an end. "The crisis will pass and end, and the question of administrative, political and press reforms will advance," Assad was quoted as telling a delegation of residents the main port city of Latakia, north of Banias. He stressed the need "to consolidate national unity because the nation is the mother of all of us and we need to unite in the face of this plot." Syrian officials claim that "terrorist gangs" and foreign hands are behind the unrest. The military launched its action in Banias and Homs after ending a 10-day lockdown in which dozens were killed and scores detained in Daraa. Rights groups say more than 600 people have been killed and 8,000 jailed or gone missing in the eight-week crackdown on protesters. The Committee of the Martyrs of the 15 March Revolution puts the death toll at 708 while the Observatory says 621 civilians were killed and 120 soldiers and security forces. The United States has warned it would take "additional steps" against Syria if it continues its deadly crackdown while the European Union decided on Friday to impose sanctions on 13 Syrian officials.