Airstrikes rocked Syria on Tuesday, killing more than a dozen people in rebel-held areas of the besieged northern city of Aleppo, and the shelling of a government-held area in a southern city killed at least six more people, activists and state media said.
Intense airstrikes were reported in Aleppo, which has seen fierce fighting in recent months as the government forces of President Bashar Assad, backed by Russian allies, try to recapture the opposition-held east, home to about 250,000 people.
In the southern city of Dara, where the war began after antigovernment protests more than five years ago, rebels fired rockets at government-held areas, according to the official Syrian Arab News Agency, or SANA. One hit an elementary school, killing half a dozen people — among them five children — and wounding 18 students, the news agency reported.
Shelling by opposition groups was also reported in the capital, Damascus, including close to the Umayyad mosque, considered one of the oldest and holiest in the world, according to SANA.
Fighting has intensified in recent weeks after the collapse of a cease-fire brokered by the U.S. and Russia.
The British-based Syrian Observatory for Human Rights, which monitors the conflict, said at least eight people were killed in east Aleppo's Bustan al Qasr and Fardous neighborhoods Tuesday, but residents said the toll was higher.
Amar Salmo, 32, who leads the area's civil defense volunteers, said more than 40 people were killed and more than 70 injured.
"The last week was so calm, so quiet. Today was so explosive — more than 20 of these attacks were bunker-buster [bombs] and these make a lot of damage," he said, referring to powerful explosives capable of penetrating underground shelters.
Salmo and 120 volunteers worked to rescue victims from the rubble, many of them families. In Bustan al Qasr, they found four apartment buildings razed and a woman standing beside the ruins, just back from the market.
"She returned home and asked, where is my building? Where are my children?" Salmo said. "We were searching for dead bodies. The neighbors told her, 'This is your building and your family is under the rubble.' We dug out about 15 persons."
East Aleppo has faced intense aerial attacks since last month, when a Sept. 12 cease-fire collapsed after a week. Syrian government forces have also mounted a ground offensive into rebel-held areas of the city.
"Everything is getting worse," said Ismail Abdullah, 29, another civil defense volunteer reached by phone in Aleppo.
He said he knew of 16 people killed in the airstrikes Tuesday, seven of them children.
"We are waiting for the next hour, for the night, to see if the situation will get worse," he said.
The volunteers, known as White Helmets, fear they will be targeted and have moved their office, he said. They also worry about running out of fuel for ambulances. They have enough to last a week, but maybe not a month, Abdullah said, especially if the attacks increase.
"Maybe in coming days we will run out of everything," he said.
Hospitals in east Aleppo have been receiving an average of 86 injured people a day but are down to 11 ambulances, according to government figures cited by the nonprofit Doctors Without Borders. Five ambulances were bombed during the last month, two of which were destroyed, the group said.
"The whole world is witnessing the suffering of east Aleppo, a population trapped in a bloody battle without any chance to escape," said Pablo Marco, Doctors Without Borders' operations manager for the Middle East. "Syria and Russia must stop the indiscriminate bombing of the city. All warring parties must facilitate and allow the evacuation of the severely wounded and sick."
Krista Armstrong, a spokeswoman for the International Committee of the Red Cross in Geneva, said it has been difficult to deliver aid when cities across Syria "have seen unprecedented levels of violence recently."
"The needs are rising but we need to see a cessation of violence in order to get to these areas," Armstrong said, noting the organization hasn't been able to reach east Aleppo since April.
During an emergency session on Syria by the British Parliament, Foreign Secretary Boris Johnson called for protests outside the Russian Embassy.
Johnson said he would consider a proposal to establish no-fly zones in Syria but warned of the potential consequences.
"We cannot commit to a no-fly zone unless we are prepared to ... shoot down planes or helicopters that violate that zone. We need to think very carefully about the consequences," he said.
Instead, he urged diplomacy, "to persuade the Russians that it is profoundly in the interests of Russia to take the initiative, to win the acclaim of the international community, do the right thing in Syria … stop the bombing and bring peace to Aleppo and have a genuine cease-fire."
U.S. State Department spokesman John Kirby also called for an end to the airstrikes at a Tuesday briefing.
"What needs to happen is a cessation of hostilities," Kirby said.
He said U.S. officials believe the cease-fire could be revived if Russian counterparts signal a willingness to participate.
Salmo, the Aleppo civil defense leader, urged the international community to act soon, noting that with shortages in the city, "every day is worse than the day before, even without the bombardment."
"The people want peace, the right to sleep, eat, have medicine. We have hope, someday, this madness will be stopped," he said. "But we don't know when, and we are fed up with the statements of condemnation. We need some action, some political will to end this."