A medical facility is seen after it was hit by airstrikes in Syria's northern Idlib province, Nov. 25, 2016, in a photo provided by the Shafak Charity Organization.
FILE - A medical facility is seen after it was hit by airstrikes in Syria's northern Idlib province, Nov. 25, 2016, in a photo provided by the Shafak Charity Organization. A similar facility was hit Wednesday in Idlib, in the town of Ma’aret Hurmeh.

Two medical workers affiliated with a U.S.-based medical group were killed Wednesday in an attack in northwestern Syria, the medical relief group said. A third medical volunteer was killed in the same attack.

Six airstrikes targeted an ambulance center in the town of Ma’aret Hurmeh in Idlib province, said the Syrian American Medical Society (SAMS) in a statement.  

The facility and the ambulance were completely destroyed, the group added.

“These blatant crimes and violations of [international humanitarian law] must be investigated to hold perpetrators accountable,” said Mufaddal Hamadeh, SAMS President.

Local reports said the airstrikes that targeted the medical facility in Idlib were carried out by Russian warplanes.

The medical workers “were killed in the airstrikes as they were trying to rescue civilians wounded in the ongoing aerial bombardment,” Horrya Press, an opposition website said.

FILE - A wounded man is treated at a medical center of the Syrian American Medical Society (SAMS) following reported airstrikes, in the town of Kfar Batna, Syria, June 11, 2016.

The Syrian Observatory for Human Rights, a war monitor that has researchers throughout the war-torn country, said at least seven people were killed in Wednesday’s attacks on Idlib.

SAMS is a Syrian-American non-profit organization that is dedicated to providing medical relief to victims of Syria’s civil war.

850 medical workers killed since 2011

The While Helmets, the volunteer group that has gained international recognition for their humanitarian work in Syria, said Wednesday that one of its volunteers was also killed in the Russian airstrikes on Idlib.

 The World Health Organization says that “medical workers [in Syria] have been repeatedly attacked, and there is an intense shortage of trained staff.”

Since the beginning of the Syrian conflict in 2011, more than 850 medical workers have been killed, according to SAMS.

U.N. Secretary-General Antonio Guterres has authorized an inquiry into attacks on civilian infrastructure including hospitals, clinics and schools in Idlib.

Russian and Syrian governments deny targeting medical facilities used by civilians.

In a recent letter to the U.N., Syria’s U.N. Ambassador Bashar Ja’afari said that “all health-care facilities in Idlib have been rendered inoperative since the terrorist groups overran them.”

Battle for Idlib

For months, Syrian government forces, backed by Russian warplanes, have been targeting towns and villages across the northwestern province. Idlib has been a rebel stronghold since 2015.

In September 2018, Russia and Turkey reached a deal to create a buffer zone to avoid a Syrian regime offensive on Idlib, but the agreement has not been fully implemented.   

The Syrian Observatory said that at least 3,000 people, including 900 civilians, have been killed since the fighting has escalated in recent months.  

On Wednesday, Syrian regime troops recaptured four villages in the southern part of Idlib, Syria’s official news agency SANA said.

The ongoing offensive in Idlib caused “heavy losses in the personnel and equipment upon terrorist organizations which were positioned there,” SANA added.

The Syrian government considers all rebel groups operating in the country as terrorists.