BEIRUT — Syrian government warplanes and artillery pounded rebel-held districts of Aleppo for the second day Wednesday, killing at least 11 people and damaging two hospitals, a blood bank and several residential buildings in the city’s eastern neighborhoods.

Residents rushed for cover and doctors cowered with their patients in a hospital basement amid the relentless onslaught. Local activists said they counted about 50 artillery and airstrikes since the morning hours.

The resumption of airstrikes on besieged Aleppo began Tuesday as Russia announced its much-anticipated offensive in Syria’s north and central Homs province. Meanwhile, activists reported the airstrikes on besieged Aleppo.

The Britain-based Syrian Observatory for Human Rights said at least 32 civilians have been killed since the bombardment resumed on Tuesday after a nearly four-week respite for the city’s eastern, rebel-held quarters.

The local Civil Defense rescue group, also known as White Helmets, reported that 11 civilians were killed in the Sukkari neighborhood on Wednesday alone.

Survivors described the horrific assault and videos posted on social media showed rescuers working through the afternoon to pull victims from the rubble of bombed buildings.