The international community must band together in pressuring Syrian leader Bashar Assad to step down and put and end to the killing of Syrian citizens, US President Barack Obama said on Friday. His comments came as rescue workers began evacuating wounded civilians from a besieged Syrian city."All of us seeing the terrible pictures coming out of Syria and Homs recently recognize it is absolutely imperative for the international community to rally in sending a clear message to President Assad that it is time for a transition," Obama told reporters."It is prime time to stop the killing of Syrian citizens by their own government," he said after a meeting with Danish Prime Minister Helle Thorning-Schmidt of Denmark. Meanwhile, the Syrian Arab Red Crescent began evacuating wounded or sick women and children from the Baba Amro district of the besieged city of Homs on Friday as international pressure mounted on the Syrian government to open the country up to humanitarian aid.The International Committee of the Red Cross (ICRC) said the evacuation was underway after Syrian Arab Red Crescent ambulances had entered Baba Amro. "It's a first step forward," ICRC chief spokeswoman Carla Haddad told Reuters in Geneva.News of the evacuation came as Gulf Arab nations meeting in Tunis pushed for more forceful intervention against Syrian President Bashar Assad and the United States warned he would have "even more blood on his hands" if he blocked aid to stricken civilian areas.Speaking at the meeting called to escalate pressure on Assad over his crackdown on 11 months of protests, Saudi Arabia's Foreign Minister Prince Saud al-Feisal said he supported arming the rebels."I think it's an excellent idea," he said at the start of a meeting with US Secretary of State Hillary Clinton, who warned Assad would pay a heavy price for the violence in Syria."If the Assad regime refuses to allow this life-saving aid to reach civilians, it will have even more blood on its hands," Clinton said in prepared remarks for the meeting. "So too will those nations that continue to protect and arm the regime".With the bombardment of opposition-held neighborhoods in Homs entering its fourth week on Friday, the city has become the most internationally known focus of the violent crackdown on opposition in Syria.Opposition activists said earlier on Friday that Syrian government artillery fire killed five people."Baba Amro is being hit with 122mm artillery directed at it from surrounding villages. A father and his 14-year-old son were among those killed. They were trying to flee the shelling when shrapnel hit them in the street," Mohammad al-Homsi said.The International Committee of the Red Cross, which had been negotiating with Syrian officials and opposition forces in Homs for an evacuation of all sick and wounded in need of help, gave no further details of its operation.ICRC spokeswoman Carla Haddad said there was no immediate information from the humanitarian agency's teams on the ground as to whether wounded foreign journalists were among them.French Foreign Minister Alain Juppe had said the Red Cross and the governor of Homs were working to evacuate the foreign journalists stranded in the city.Activists also said Syrian security forces lined up and shot dead at least 18 people in a village in the central western Hama province. A video uploaded by activists showed people wrapping the bloodied bodies of children and at least four adults. Several had been shot through the head.