Jane Onyanga-Omara, and Oren Dorell

USA TODAY

An airstrike on a hospital in the rebel-held Syrian city of Aleppo Thursday killed at least 27 people, the latest in what Amnesty International calls a recurring tactic in the Syrian civil war.

Days of airstrikes and shelling in Aleppo, which is split between President Bashar Assad's government forces and rebels, have killed about 200 people in Syria in the past week, according to the British-based Syrian Observatory for Human Rights.

Doctors Without Borders, which supports the hospital, expects the death toll to rise. The international aid organization said the facility in Aleppo was hit by a direct airstrike and among the dead are at least three doctors, including one of the last pediatricians in the city.

It wasn’t immediately clear who was responsible for the strike.

White House press secretary Josh Earnest called the airstrike "appalling," saying the attack "fits the Assad regime's abhorrent pattern of striking first responders."

He also said the strikes put pressure on the already fragile peace talks in Geneva.

Najib al-Ansar, a Syrian Civil Defense official in Aleppo, said the hospital was hit by Russian airstrikes, according to Turkey’s Andalou Agency. The Syrian opposition accused the government of Damascus and Russia for the bombings. But Russia denied it was responsible. The Russian Defense Ministry spokesman, Maj. Gen. Igor Konashenkov, said Russian aircraft have not flown any missions in the region in the past several days, the Associated Press reported.

Greg Archetto, a former Defense Department official who worked with members of the Syrian armed opposition in Jordan, said the Russians and Syrians are fighting to win the war in Syria, and have little regard for how it looks to outsiders.

"The Russians don't care about international public opinion and neither does Assad,” Archetto said. "Destroying the enemy is the goal and they are doing that from their perspective. Whether or not it is morally right is inconsequential. They have their strategic objectives and they are achieving them."

Chris Harmer, a Syria analyst at the Institute for the Study of War in Washington, said it’s unclear if the hospital was deliberately targeted, but the airstrike "is consistent with the Assad regime strategy of killing or depopulating any civilian population opposed to his rule.”

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"It is beyond dispute that the Assad regime has deliberately targeted hospitals in the past,” Harmer said. "The Syrian strategy of killing or depopulating civilians has been relatively effective at preserving the Assad regime and gradually attriting and degrading the human and geographical terrain controlled by the rebels."

Amnesty International said in a statement last month that Syrian and Russian forces have been deliberately attacking health facilities as "part of their military strategy."

Charles Lister, a Syria analyst at the Middle East Institute, agreed, saying that "targeted destruction of key sources of civilian services, like hospitals, schools, markets and IDP camps, has been commonplace."

"Destroying such targets prior to a major ground operation acts to fundamentally undermine the capacity for the opposition to present a viable alternative," Lister said."It also helps to encourage mass displacement of civilians, which further destabilizes the eventual target of attack."

The attack highlights the deterioration of a cease-fire agreement that had been agreed to in February. Russia and the Assad regime have ramped up attacks in recent days. "It is not being completely abided by, especially by Syrian regime," Defense Secretary Ashton Carter said in congressional testimony Thursday.

"We condemn the destruction of the Al Quds hospital in #Aleppo, depriving people of essential healthcare. Hospitals are #notatarget, #Syria," Doctors Without Borders, also known by its French name MSF (Médecins Sans Frontières), tweeted.

It said the hospital was the main referral center for pediatrics and had an ER, an Out Patient Department, an intensive care unit and an operating theater, all of which were destroyed.

Robert Mardini, director for the Middle East at the International Committee of the Red Cross, said that organization also supported the hospital and condemned the attack.

The incident is the latest bombing of a Doctors Without Borders-backed hospital.

In February, Russia denied bombing a hospital funded by the organization in Idlib province, northern Syria, after the United States and aid groups blamed it and the Syrian government.

U.S. forces bombed a Doctors Without Borders hospital in Kunduz, northern Afghanistan, on Oct. 3, killing 30 people. Later that month, a Doctors Without Borders facility in Saada, northern Yemen was hit by multiple airstrikes.