BEIRUT Rebels battled Syrian troops in the eastern border city of Qamishli on Friday, a monitoring group opposed to President Bashar al-Assad said, ending a de facto truce in the mainly Christian and Kurdish area.
Qamishli, on the border with Turkey and close to Iraq, has remained peaceful during a two-year uprising against Assad because local Kurds agreed with mostly Arab rebels to avoid clashes within city limits, said the British-based Syrian Observatory for Human Rights.
Videos posted on the Internet on Friday showed pickup trucks and dozens of rebels preparing an attack on Qamishli's domestic airport and smoke rising from the airport grounds.
The city of around 200,000 is also home to thousands of Syrians who have fled other parts of the country, the Observatory said. Inhabitants must now wait and see whether Assad retaliates for rebel attacks by using war planes, as he has done in other major cities.
The Observatory said the advance includes rebels of the Free Syrian Army and the hard-line Islamist Nusra Front, who have clashed in the past with Christians and Kurds the opposition has tried to persuade to abandon Assad.
"We are not sure why they are attacking today," said Observatory head Rami Abdelrahman. "Maybe the agreement broke down," he said, adding that the government and Kurdish militia control different areas of Qamishli.
In January, Kurdish militants and rebels fought battles with each other for weeks after Assad's forces retreated from Ras al-Ain, a northern border post with Turkey, embarrassing an opposition movement that said it speaks for all Syrians.
More than 70,000 people have been killed in Syria's war, according to the United Nations. March was the conflict's bloodiest month yet, with more than 6,000 people killed, a third of them civilians, according to the Observatory.
Protests against the Assad family's four-decade rule broke out in Qamishli in April 2011, Kurdish activists said at the time. Kurds, around 10 percent of Syria's population, faced discrimination and harassment under Assad and his father, Hafez.
But after a crackdown by Assad's forces on peaceful demonstrations and the subsequent arming of the opposition, many of Syria's Kurds distrust the rebels and there have been sectarian clashes over the past few months across the country.
The Syrian government has given Kurdish militia autonomy over some areas on the condition rebels are kept out.
Western and Middle Eastern nations trying to help the opposition will meet in Turkey on April 20.
(Reporting by Oliver Holmes; Editing by Jason Webb)