AMMAN - Syrian rebels said police had opened fire and killed two people on Tuesday when a crowd turned out to greet a team of UN ceasefire monitors in the eastern province of Deir al-Zor. A United Nations spokeswoman said the team had heard gunfire but said they had not seen any casualties. The UN team was part of a contingent of about 260 unarmed observers sent to Syria to monitor an internationally-brokered ceasefire in the conflict between President Bashar al-Assad and opponents trying to overthrow him. Government forces have been widely condemned for their repression of the uprising but both sides have regularly violated the ceasefire. Abu Laila, a Free Syrian Army official, told Reuters by phone from the town of al-Busaira: "As soon as the UN convoy entered al-Busaira, a jubilant crowd of hundreds came out to welcome them. It was not minutes before they came under fire." Another opposition source in the province said government forces surrounding al-Busaira had fired anti-aircraft guns at the town. The spokeswoman for the monitors, whose mission is part of a peace plan laid out by UN-Arab League envoy Kofi Annan, said the U.N. team had heard gunfire near the town but had no information on casualties. "A group of villagers from elsewhere followed the U.N. patrol to al-Busaira, which is government-controlled. They were asked not to follow the patrol into the town," she said. "The team left by another checkpoint to avoid any contact between the military and villagers, and there they heard the use of heavy weapons." Claims from both sides in the conflict are hard to confirm independently as Syria restricts access for most journalists. Deir al-Zor, an oil-producing province bordering Iraq, has often seen skirmishes in recent months between insurgents and government troops trying to regain control of rebel-held areas.