BEIRUT: ISIS jihadists advanced for the first time Sunday into a military airport that is the last stronghold of the Syrian army in Raqqa province, an activist group said.
The Syrian Observatory for Human Rights said fighters from the group had launched a fourth attack in six days on Tabqa military airport overnight and entered the facility Sunday morning.
" ISIS launched a new attack on the airport, which is the fourth since Tuesday," said Rami Abdul-Rahman, director of the Britain-based Observatory.
"They were able to enter it for the first time, but they don't yet control the facility," he added.
Abdul-Rahman said the jihadists had also seized several checkpoints, hanging up at one the head of a soldier who had been killed in the fighting and decapitated.
There was no immediate death toll in the latest fighting that began overnight, but at least 100 ISIS fighters and 25 regime troops had been killed before the new clashes.
Regime forces have repelled three previous attacks on Tabqa air base.
Regime warplanes have backed forces on the ground and carried out six new raids Sunday on different targets.