Orient Net,  Feb,  19,  2018—  Dr. Mohammad Katoub of the Syrian American Medical Society (SAMS), which works in opposition areas of Syria and other doctors visiting Brussels this week for meetings with European officials told NBC News that bombings in opposition strongholds had spiked since the beginning of the year with an average of one health facility hit every 24 hours.

SAMS representatives said Russian and Assad forces had escalated their attacks even further on Eastern Ghouta and Idlib in the past two weeks.

An overall increase in attacks on hospitals, clinics, ambulances and other health facilities tracks Russia’s involvement in the war, which began in earnest in the fall of 2015, according to SAMS.

While the SAMS doctors admit they cannot prove which strikes are Russian and which are work of the Kremlin-backed military of Bashar al-Assad, they cite the use of more sophisticated and powerful weapons as evidence of Moscow’s involvement.

Medical workers have responded by building hospitals deep underground, but that has not stopped the destruction and death.

“We noticed different types of weapons being used since the Russian intervention — especially those mass destruction weapons like bunker buster weapons, for example, that can penetrate the fortifications that we have built,” Katoub said. “We fortified our hospitals, we used hospitals underground, we dug caves, and we tried to protect our staff by ourselves.”

But since the Russians got involved, he said, “we’ve noticed that advanced weapons are used to penetrate those fortifications.”

The Russian Defense Ministry did not immediately respond to NBC request for comment.

There were more than 400 attacks on medical facilities across the country in 2016, according to SAMS. That number fell to 110 last year but has jumped to an average of one a day since Jan. 1, the group added.

Since 2012, more than 800 health workers have been killed in various attacks on the medical facilities, according to SAMS.

This month, the United Nations called for an immediate month-long humanitarian cease-fire to prevent civilian suffering and deaths.

Hundreds of civilians have been killed in Eastern Ghouta — which the International Committee of the Red Cross estimates is home to 400,000 people — and in Idlib this year, according to UN rights chief Zeid Ra‘ad al-Hussein.