BEIRUT, Lebanon — Eight hospitals bombed in the past week, five of them within the last 48 hours. Food stores running out of supplies. Scores of people killed in a single day.
By Wednesday night, it was clear that the escalation feared for weeks in rebel-held parts of northern Syria was underway, as Russian and Syrian government warplanes carried out a second straight day of intense bombardment.
The attacks have stretched across several provinces, shattering a rare interval of several weeks without airstrikes in the rebel-held districts of Aleppo. The respite there ended after the Syrian and Russian governments announced that the last chance for civilians and fighters to leave east Aleppo or surrender had expired.
The latest bombings spurred a new sense of alarm from hungry, tense residents, as well as from humanitarian agencies that had warned of growing violations of international law — particularly what they described as a pattern of deliberate attacks on health care facilities.
Airstrikes on Wednesday damaged two hospitals in Aleppo, including one for children, and a blood bank.
Those attacks followed bombings on Monday of three other hospitals in the western suburbs of Aleppo that killed two health workers and wounded 16, leaving thousands of people without access to medical care.
“Shockingly, such attacks on health in Syria are increasing in both frequency and scale,” the World Health Organization said in a statement. “This is a major violation of international law and a tragic disregard of our common humanity.”
Russia says that its attacks have been focused on insurgents in Homs and Idlib Provinces and that it has not carried out bombings in Aleppo, suggesting that the attacks there were by the Syrian government.
In any case, at least 34 people died in the city on Wednesday, including six children, according to doctors there. In addition, 26 people were killed in a suburb.
For Abdelkafi al-Hamdo, a schoolteacher and antigovernment activist in the eastern part of Aleppo, the attacks escalated the mounting stress on his family. His 9-month-old daughter survives only by nursing; his wife is ill, and he took her to a hospital only to be caught in one of the bombings, he said.
“While we were there, that horrible sound was near to us,” he said in a text message. “They told us to leave cuz many casualties were expected. We waited cuz the planes were in the sky.”
Zaher Azaher, another resident of eastern Aleppo, said that his home had been hit for a second time. “Life is upside down here,” he said.
Wissam Zarqa, a teacher in the area, said the attacks were bewildering because during the pause in airstrikes, government forces had managed to repel a rebel counteroffensive and advance on the ground.
“So what’s the point of targeting residential neighborhoods?” he said.
Tensions have flared in the rebel-held area, with infighting between rebel groups, disputes over scarce food, and rescuers unable to reach all the trapped and injured.
Mr. Zarqa said his students had told him of a man who demanded that rescuers pull his wife and child out of the rubble of their house, but they could not come right away because they had no fuel. The man was so angry he punched an ambulance window and had to be hospitalized, the students said.
Bassem Ayoub, an activist in eastern Aleppo, said flour was running out, even as warplanes continued “hovering freely in the sky” since Tuesday morning.
Only one bakery was still operating in his neighborhood, Mashhad, but not for long, he said: “The owner said he would close it after he bakes the last bag of flour.”
Humanitarian officials warned last week that an estimated 250,000 people in Aleppo, down to their last rations, were in grave danger.
On Tuesday, protests erupted in rebel-held parts of Aleppo, with angry, hungry residents leveling accusations of corruption against those in charge of aid distribution. Some warehouses were opened and food taken.
There were several competing versions of how events unfolded, but some reports said that rebels had fired over the heads of the crowd to prevent people from taking the remaining rations.
Hisham Skeif, a member of a local council of rebels and civilians, confirmed that the protests had taken place.
“People are hungry, we understand, but we’re trying to keep things under control, there is oppression, there is anger, I do agree, but the regime is triggering reaction, using starvation as an excuse,” he said.
The Russian deputy foreign minister, Sergei A. Ryabkov, told the news agency Interfax on Wednesday that Moscow’s airstrikes in Syria were targeted, proportionate and measured, and that its current operations were aimed at the provinces of Idlib and Homs.
But more could be on the way. The Russian daily Kommersant reported that Russian airstrikes could soon resume in Aleppo.