NEW: Car bomb blast in Damascus countryside, no word on deaths The Red Cross says it's struggling to cope with Syria's worsening humanitarian situation 50 Syrian soldiers killed in suicide bombing, opposition says Syrian rebels blame 'heinous' executions on 'extremists' Representatives from Britain, France, the United States and Turkey are meeting in Qatar Thursday to try to ensure Syria's opposition is represented by more than just the Syrian National Council. Meanwhile, Turkey urged the international community to do more to support Syrian-led efforts to resolve the crisis, and warned against further delay. "There is not a moment to lose," Turkish Foreign Minister Ahmet Davutoglu told delegates in Doha, Qatar, Thursday, according to Turkey's semiofficial Anadolu news agency. U.S. identifying possible leaders in Syrian opposition The Red Cross is unable to "cope" with the increasingly deteriorating humanitarian situation in Syria, Peter Maurer, president of the International Committee of the Red Cross, said in Geneva, Switzerland, Thursday. "The seriousness of the crisis is deepening every day and this trend has been uninterrupted since the summer," he said. There are a number of blind spots where we know no aid has reached the population. Aid workers have to contend with a complex situation and obstacles on the ground that include security threats and military or bureaucratic restrictions on access, ICRC spokeswoman Carla Haddad Mardini said. "We try to fill the cracks which open, and whenever we have an opportunity to deliver aid, we go ahead," Maurer said. At least 64 people have died in Syria so far Thursday, according to the Local Coordination Committees, an opposition activist network. Of those, 22 were killed in Damascus and its suburbs, the LCC said. A car bomb exploded in Sayda Zainab, a neighborhood in the Damascus countryside, according to the Syrian Observatory for Human Rights, a London-based opposition group. There was no immediate information on how many people were killed. Saida Zaynab is home to a historic Shia shrine that draws thousands of pilgrims every year. Fighting between loyalist Syrian forces and fighters from the Free Syrian Army also raged along Syria's border with Turkey, leading Turkish authorities to close schools in the border town of Ceylanpinar. The Syrian Observatory for Human Rights also said at least 10 rebels and 16 Syrian troops were killed on the Syrian side of the border, in Hasaka province. Some rebels entered Syria from Turkey and engaged the Syrian army in clashes, the group said. At the same time, Turkish President Abdullah Gul said his country was drawing up contingency plans with the NATO military alliance to fortify its border with Syria. Gul told reporters Thursday that because of the ongoing civil war in Syria and its possible repercussions for NATO member Turkey, every measure was being considered to counter the risks. Turkish and international media have reported in recent days those options include the installation of Patriot missiles along the border, something Prime Minister Recep Tayyip Erdogan denied Wednesday. Several stray mortar rounds and a tank shell landed Thursday in the Golan Heights -- captured by the Jewish state from Syria in the 1967 Six-Day War -- as a result of fighting inside Syria, according to the Israeli military. One of the shells landed in the Israeli settlement of Alonei HaBashan, but there were no reports of damage or injuries, the Israeli military said. CNN's Arwa Damon, Ivan Watson and Salma Abdelaziz contributed to this report.