BEIRUT (AP) -- A Syrian military aircraft crashed into the de facto capital of the Islamic State group on Tuesday, killing at least eight people, as thousands of residents fled to nearby villages in anticipation of expected U.S. airstrikes against the militants, activists said.
It was not immediately clear whether the plane that slammed into the northeastern city of Raqqa was hit by anti-aircraft fire or experienced a technical failure, according to an activist based in the city and the Britain-based Syrian Observatory for Human Rights.
The Raqqa-based activist, who goes by the name Fourat Alwfaa, said eight people were killed in the crash, including members of two families after the aircraft plowed into their home. The Observatory said there were casualties, but did not have a concrete figure.
The Islamic State group controls a proto-state that stretches from northern Syria across much of northern and western Iraq. Raqqa, an ancient city on the Euphrates River with a prewar population of 500,000, serves as the extremists' stronghold in Syria.
The U.S. has been conducting airstrikes against Islamic State fighters in Iraq since the militants tried to push toward the northern city of Irbil in Iraq's largely autonomous Kurdish region in August. President Barack Obama last week authorized strikes against the group in Syria as well, and his administration is currently trying to cobble together an international coalition to go after the group.
As international attention has zeroed in on the extremists, the Syrian government, which largely shied away from bombing the group's territory for more than a year, has begun targeting cities and towns under the militants' control more frequently.
Those government strikes, and perhaps even more-so the prospect of an American-led aerial campaign that is all but certain to target Raqqa, have prompted many residents to pack up and move to outlying villages, according to Alwfaa and another resident.
"By God, yes, people began fleeing about a week ago," said a woman who requested anonymity, fearing identification by the militant group. She said they fled to nearby villages, away from the militant group's bases.
Previous Syrian airstrikes killed dozens of civilians in Raqqa. Alwfaa said residents feared U.S. strikes would cause even more damage.