Syrian opposition demands trio's release Syrian anti-regime activists called on Sunday for the immediate release of three colleagues they say were seized by security agents as they drove home from Damascus airport after a trip to China. The trio's disappearance on Thursday overshadowed a one-day conference in the capital of members of the embryonic licensed opposition, who voiced fears for the men's safety, and drew up posters calling for their freedom. "It wasn't the Free Army - it was the government for sure," said a member of the National Co-ordination Body, of the disappearances. Of course we were all talking at the conference about all the other people who have been arrested for reasons we don't know. The government and the rebel Free Syrian Army - which has announced that its leadership has moved from Turkey to Syria - have blamed each other for the trio's seizing, which highlights the dangers facing even government-sanctioned peaceful opposition groups amid the civil war. Demands for the men's release came as violence flared throughout the country at the weekend, with 214 people killed on Saturday alone, including 140 unarmed civilians, according to the UK-based Syrian Observatory for Human Rights, a pro-opposition monitoring group. The three members of the NCB - Abdel Aziz al-Khair, Eyas Ayyash and Maher Tahan, who had met them at the airport - vanished as they travelled into Damascus on Thursday night. A member of the NCB said their delegation to Beijing had been met at the aircraft by a member of air force intelligence, widely seen as the most brutal of the country's many security agencies. Mr Khair and the rest of the delegation were then allowed to leave the airport in two cars - but only one made it safely to the city centre. "I think air force security took the three guys," said the NCB member, who said the men had been discussing the nation's crisis with authorities in Beijing, one of the Syrian regime's main defenders. The security services thought that if they took them, they would make a problem for the conference. Outside the conference hall - where diplomats in attendance included officials from Russia and Iran, the Assad regime's two strongest backers - activists drew up pleas on large pieces of white paper for the return of the three men and "freedom for all our jailed people." One foreign diplomat said there was still too little information to say conclusively what had happened to the trio. While armed Syrian opposition militias have been implicated in kidnappings and are active in areas close to the Damascus airport road, the highway is under government control and is secured by groups of soldiers posted at intervals along the route. Independent rights groups say the regime has arbitrarily detained large numbers of people, some of whom have been tortured and murdered, as it has cracked down brutally on the 18-month old uprising. Meanwhile, the announcement by the self-styled head of the FSA, Colonel Riad al-Asaad, of the shift to Syria is widely seen as an attempt to stake a stronger claim to leadership over the disparate rebel units, many of which do not nominally operate under the FSA umbrella. In a video announcing the move, Col Asaad said the FSA leadership had entered "liberated" territories of Syria. Some northern parts have become no-go areas for regime ground forces in recent months. But an intense campaign of government aerial bombardments means that even these zones are risky for rebels. The FSA's proclaimed push into Syria comes as international concern grows over the emergence of more radical fighting groups. It also comes amid controversy in Turkey over rebel activities on Turkish soil. Last month, a website claiming to represent the FSA said the organisation's main base was in Turkey's southern province of Hatay - but the statement was removed after an outcry. Opinion polls indicate that up to two-thirds of Turks oppose Ankara's stance on Syria, which has included hosting both the political and military opposition and championing calls for President Bashar al-Assad to step down. Many Turks express fears about military confrontation with Damascus. Additional reporting by Daniel Dombey in Istanbul