A convoy of inspectors from the Organization for the Prohibition of Chemical Weapons prepares cross into Syria at the Lebanese border crossing point of Masnaa, eastern Bekaa Valley, Lebanon, Tuesday, Oct. 1, 2013. BEIRUT (AP) - International inspectors racing to eliminate Syria's chemical weapons stockpile said Thursday they have made "encouraging initial progress" in their mission, and they hope to start onsite inspections and to begin disabling equipment within a week. An advance team of disarmament experts arrived in Syria on Tuesday to begin laying the foundations for a broader operation charged with dismantling and ultimately destroying President Bashar Assad's chemical program over the next nine months. The first step in the undertaking - endorsed by a United Nations Security Council resolution last week - is to scrap Syria's capacity to manufacture chemical weapons by Nov. 1. The team reported its progress in a statement issued after the first day of meetings with Syrian authorities. Documents handed over by the Syrian government "look promising," the statement said. But more analysis, particularly of technical diagrams, was planned, and "more questions remain to be answered." The onsite inspections and the disabling of equipment depend on the work of technical groups established together with Syrian experts. Those groups, the statement said, are working to iron out the details in three areas crucial to the mission: verifying the initial information Syria provided on its chemical program, ensuring the safety of the inspectors and finalizing practical arrangements for implementing the plan. Early Thursday, a convoy of three U.N. vehicles left a hotel in central Damascus with nine experts from the Netherlands-based chemical weapons watchdog, but it was not clear where they were heading. For now, the team consists of an advance group of 19 experts from the Organization for the Prohibition of Chemical Weapons and 14 U.N. staff members. A second group of inspectors is to join them within a week to raise the total number to nearly 100. Their mission stems from a deadly Aug. 21 attack on opposition-held suburbs of Damascus in which the U.N. has determined the nerve agent sarin was used. The U.S. and its allies accuse the Syrian government of being responsible for the attack, while Damascus blames the rebels. The Obama administration threatened to launch punitive missile strikes against Syria, prompting frantic diplomatic efforts to forestall an attack. Those efforts concluded with last week's unanimous U.N. Security Council resolution endorsing the elimination of Syria's chemical weapons. The mid-2014 deadline - the tightest OPCW inspectors have faced - is only one of several challenges the inspectors must overcome. Another major hurdle is purging Assad's estimated 1,000-ton arsenal in the middle of Syria's bloody civil war. The conflict, which is rooted in what began as peaceful protests in March 2011, has laid waste to the countries' cities, shattered its economy and driven more than 2 million people to seek shelter abroad. The violence affects every corner of Syria, which has become a patchwork of rebel-held and regime-held territory. In recent months, an outburst of infighting among the myriad rebel groups opposed to Assad added another layer to an already complicated conflict. Al-Qaida-linked fighters in Syria have been some of the most effective forces on the battlefield, and they often fight alongside more moderate rebel brigades against government troops. But with growing frequency, Islamic extremist fighters and more mainstream rebels also are turning their guns on each other. Turf wars and retaliatory killings have evolved into ferocious battles that have effectively become a war within a war in northern and eastern Syria, leaving hundreds dead on both sides. One of the worst instances broke out late last month in the town of Azaz near the Turkish border as the al-Qaida-affiliated Islamic State in Iraq and the Levant battled the more moderate Northern Storm Brigade linked to the Western-backed opposition. In a statement released late Wednesday, six rebel groups urged ISIL and the Northern Storm Brigade to "cease fire immediately" and resolve their differences before an Islamic court. The appeal also called on the al-Qaida-linked ISIL to withdraw its fighters to areas where they were before the clashes in Azaz erupted late last month. The appeal's signatories included the Islamic Army, the Tawheed Brigade and Ahrar al-Sham - three of the most powerful rebel groups. Associated Press writer Barbara Surk contributed to this report.