Government bombardment of besieged rebel-held neighborhoods in the northern city of Aleppo killed at least 20 people Saturday, Syrian opposition activists said, a day after the health directorate said all hospitals in opposition areas have been knocked out of service.
The onslaught began Tuesday, when Syria's ally Russia announced its own offensive on the northern rebel-controlled Idlib province and Homs province in central Syria.
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The latest deaths raise to more than 130 the number of people killed in northern Syria since Tuesday.
"The United States condemns in the strongest terms these horrific attacks against medical infrastructure and humanitarian aid workers," National Security Advisor Susan Rice said in a statement Saturday. "There is no excuse for these heinous actions."
The bombing came after a day of airstrikes that hit four hospitals in east Aleppo. A statement issued late Friday by the opposition's Aleppo Health Directorate said that all hospitals in east Aleppo are out of service because of the bombing over the past days.
"The intentional destruction of infrastructure for survival has made the besieged steadfast people, including children, elderly and men and women, without medical facilities to treat them," the statement said.
The Britain-based Syrian Observatory for Human Rights said not all hospitals in east Aleppo neighborhoods are out of service but people are finding difficulties reaching them because of the intensity of the shelling.
Opposition activists said Saturday's death toll has been the worst since the aerial campaign resumed on Tuesday. Residents said hundreds of artillery shells and dozens of airstrikes have hit the city, increasing the misery of its residents who have been suffering from lack of food and medicine because of the siege imposed by government forces and their allies in July.
"Aleppo is being wiped out in front of the eyes of the world," medical official Mohammed Abu Rajab said in an audio message to The Associated Press from inside the city. "It's not only hospitals that are out of service. All liberated areas in Aleppo are out of service."
The Observatory said Syrian government warplanes and artillery struck more than 20 neighborhoods in east Aleppo killing 27 people and wounding many others.
Pro-government media, meanwhile, reported rebel shelling on government-held parts of the city, saying they killed two and wounded others.