Syria agreed in principle Friday to allow dozens of Arab observers into the country to oversee a peace plan, a significant concession from a hard-line regime that loathes any sort of outside interference. But critics said the regime is only stalling, trying to defuse international pressure while continuing its bloody crackdown on an 8-month-old uprising which the UN estimates has killed more than 3,500 people. The acceptance came after heavy pressure from the Arab League, which brokered the peace plan and this week suspended Syria from the 22-member organization for failing to abide by it. Further international pressure was mounting on Syrian President Bashar Al-Assad. Britain appointed a senior diplomat to be its pointman in dealing with Syria's opposition, and French Foreign Minister Alain Juppe called on the UN Security Council to strengthen sanctions against the regime. However, Russia urged caution in moving against Damascus. Violence has escalated in Syria the past week, as army dissidents who sided with the protests have grown more bold, fighting back against regime forces and even assaulting military bases. The Arab League observer mission aims to prevent violence and monitor a ceasefire that Damascus agreed to last week in the League peace plan. But, deep questions remain over how effective Damascus will allow the mission to be. A senior Syrian official said Friday that the government had agreed to the observer mission in principle but was “still studying the details.” Nabil Al-Arabi, the head of the Arab League, said in a statement that he received “amendments” to the mission from Damascus. On the ground, attacks by army defectors, including one this week on an Air Force Intelligence base just outside Damascus, have raised fears of civil war, a possibility also seen by US Secretary of State Hillary Clinton. “I think there could be a civil war with a very determined and well-armed and eventually well-financed opposition that is, if not directed by, certainly influenced by defectors from the army,” she told NBC.