McCain and Graham Plan U.S. Help to Syria Rebels Pete Marovich/Getty Images Senator John McCain in Washington on Feb. 2. He said Sunday that Syrians should "have the ability to defend themselves." The senators, John McCain of Arizona and Lindsey Graham of South Carolina, both Republicans, laid out a series of diplomatic, humanitarian and military aid proposals that would put the United States squarely behind the effort to topple President Bashar al-Assad of Syria. Syria relies on Iran for financial and military support, and the governments in Damascus and Tehran have sectarian ties as well: Iran has strongly backed the Syrian Shiite minority and the offshoot Alawite sect that makes up Syria's ruling class. Syria's crackdown continued on Sunday, including action near the heart of Damascus, in the Mezze neighborhood near the presidential palace. A day after security forces opened fire on a large demonstration there, killing at least one person, residents reported a heavy concentration of troops throughout the city, apparently sent to head off another protest. At least 14 people were reported killed around the country, some by the government and some by armed opposition forces, according to the Syrian Observatory for Human Rights, an opposition group that operates out of Britain. The Syrian state news media said that three people - a senior prosecutor, a judge and their driver - were killed by an "armed terrorist group" in Idlib Province. Idlib has seen heavy fighting between government forces and an armed network of military defectors, Turkish-based opposition forces and local rebels loosely organized under the banner of the Syrian Free Army. Egypt on Sunday became the latest Arab country to withdraw its diplomatic mission to Syria. Egyptian state news media said that the nation's ambassador would leave in answer to a call by the Arab League for its members to break ties with Damascus. The Syrian Embassy in Cairo has been vacant since it was ransacked by a largely Syrian crowd two weeks ago, leaving it battered and burned. The detail in the American senators" comments, made at a news conference during their visit to the Afghan capital, Kabul, appeared to signal that these were themes they would address when they arrived in Cairo, their next stop. The senators are leading a bipartisan delegation that stopped in Kabul to meet with military officials, diplomats and President Hamid Karzai. The senators" statements supporting arming the opposition went beyond the Obama administration's public comments about Syria. After Russia and China vetoed a United Nations Security Council resolution on Syria this month, Secretary of State Hillary Rodham Clinton said that the United States would continue to "support the opposition's peaceful political plans for change," but then added: "Many Syrians, under attack from their own government, are moving to defend themselves, which is to be expected." Still, the administration has made a point of working through the Arab League and the United Nations rather than giving the appearance that the United States is trying to intervene in Syria, in part to avoid giving Iran any excuse to get involved on behalf of its regional ally, analysts say. The senators, on the other hand, cited Iran as a major reason for action in Syria, even if only indirectly. Mr. McCain said the United States would not have to send weapons directly to the opposition but could work through "third-world countries" and the Arab League. Mr. Graham also endorsed arming those who are fighting Mr. Assad, and he suggested that the Arab League, which has called for Mr. Assad's departure, could be a conduit. Reporting was contributed by Neil MacFarquhar from Beirut, Lebanon, Helene Cooper from Washington, Liam Stack from Cairo, and an employee of The New York Times from Damascus, Syria.