Helicopters struck a medical facility in Homs with barrel bombs as injured from a previous attack were being taken to the hospital, medical charity Doctors Without Borders said.
Barrel bombs hit a hospital in northern Homs on Saturday, which Doctors Without Borders (MSF) today described as a targeted "double tap" attack on the medical facility.
The MSF-supported hospital was partially destroyed by barrel bombs which were aimed at the medical facility as medics were coping with an influx of injured from an earlier bombing.
Seven people were killed - including a young girl - and dozens injured - half under the age of 15 - after three barrel bombs were dropped on the town in less than an hour.
"This bombing shows all the signs of a double-tap, where one area is bombed and then a second bombing hits the paramedic response teams or the nearest hospital providing care," says Brice de le Vingne, Director of Operations for MSF.
"This double-tap tactic shows a level of calculated destruction that can scarcely be imagined."
The attack began at 9:40 am on Saturday 28 Novembers as helicopters circled above besieged al-Zafarana town in Homs province.
A barrel bomb on a residential area killing a man and child and injuring 16 others.
While they were taken away to be treated, a second barrel bomb hit al-Zafarana hospital.
Shortly after a third barrel bomb struck the front entrance of the hospital, which was coping with an influx of injured civilians.
Patients and medical staff were hurt, and the partially destoyed medical facility forced medics to take the injured to other hospitals where some patients died on the way.
The blasts caused the hospital building and medical stocks to be destroyed, and it is unclear whether activities can resume at the facility, which was desperately relied on by the people of al-Zafarana.
"This makeshift hospital was providing a lifeline of care to around 40,000 people in al-Zafarana town and the surroundings," said de le Vingne.
"It is already a tragedy that seven people - including a small girl - have been killed, but if the hospital has to close down or reduce activities, that is a double tragedy for the people living under the permanent threat of war, with nowhere else to turn for medical assistance."
In late October, MSF reported air raids on 12 medical facilities in northern Syria have 35 patients since bombings intensified in September.
Six hospitals were so badly damaged that they were forced to close and four ambulances were destroyed by bombing.
The Syrian opposition have also accused Russia of hitting 14 medical facilities in Syria since Moscow launched air raids on rebel-held territories at the end of September.
Russian war planes also destroyed an aid convoy in northern Syria on 25 November, killing six civilians and destroying eight vehicles.
Regime war planes have been accused of frequently targeting medical facilities and other civilian infrastructure during its intensive bombardment of residential areas, often with devastating barrel bombs.