Following the attack, Russian authorities said that Syrian rebels "had exact coordinates" of the hospital that means that those parties who support militants were also responsible for the deaths of Russian doctors. However, the US State Department denied giving coordinates of the Russian mobile hospital to the Syrian opposition.
"We take these incidents extremely seriously and follow them up directly with whoever is responsible, as part of our confidential dialogue with all sides," Barth said.
"Attacking hospitals is unacceptable. Attacking medical personnel and sick and wounded is forbidden under international humanitarian law. Sadly, this is not the first time that hospitals have come under attack in Syria, and this is not the first time that medical personnel's need for protection has been violated. It again shows that there is no respect for the special status of the medical mission, whether they are civilian or run by the military or non-state armed groups. These kinds of attacks should not be happening, regardless of who is responsible," he added.
Moscow believes that the attack on a Russian military hospital in Aleppo was a planned campaign, Russian Foreign Minister Sergei Lavrov said earlier on Tuesday.