Al Qaeda's affiliate in Syria, the Nusra Front, seized a hospital in northwestern Syria on Friday, where at least 150 Syrian regime soldiers and dozens of civilians had been holed up under rebel assault for nearly a month, a monitor said.
The Nusra Front, along with other Islamist rebel factions "have taken complete control of Jisr al-Shughur hospital," said Rami Abdel Rahman, who heads the Syrian Observatory for Human Rights.
The monitoring group's head said "dozens" had managed to flee but others were killed, wounded or taken hostage, without giving exact figures.
Earlier this month, Syrian President Bashar al-Assad had pledged to free the besieged forces, saying his "army will arrive soon to these heroes trapped in the Jisr al-Shughur hospital."
The hospital complex is in the southwest of the town in Idlib province that rebels seized on April 25.
At least 150 regime forces and dozens of civilians, including families and government bureaucrats, had since remained trapped in the hospital.
Rebel groups have made a series of major gains in Idlib province, including its capital city of the same name that they seized on March 28.
And on Tuesday, rebels took control of Al-Mastumah, the regime's largest military base in the province.
The most recent Syrian regime loss caps off a particularly dismal week for Assad's forces, after the Observatory reported Islamic State (ISIS) currently controls no less than half of the country's entire territory.
It was reported Friday that ISIS seized the last Syrian-Iraqi border crossing held by the Syrian regime, furthering strengthening and expanding the group's hold.
AFP contributed to this report.