BEIRUT -- Airstrikes in rebel-held areas in and around the northern Syrian city of Aleppo on Tuesday killed at least 15 people, including at least one child and five volunteers with a rescue service, opposition activists said.
Ibrahem Alhaj from the Syrian Civil Defense, which conducts search-and-rescue operations in rebel-held areas, said government jets carried out some 40 airstrikes in rebel-controlled areas in Aleppo that killed 10 people and wounded more than 40.
The daytime airstrikes came after at least five pre-dawn air raids on a training center run by the Civil Defense in Atareb, a city west of Aleppo, which killed five first responders.
The Civil Defense said in a statement that one of the strikes directly hit the shelter attached to the building where the volunteers took cover. The strikes also hit ambulances and firetrucks, and a rocket was fired at the center from a government-held area, the statement said.
The Britain-based Syrian Observatory for Human Rights confirmed the strikes. The monitoring group, which relies on a network of activists inside Syria, said pro-government forces launched two other rockets at Atareb on Tuesday. The Observatory said 11 people were killed in the strikes on rebel-held areas of Aleppo.
Video from the Civil Defense shows volunteers pulling the body of a toddler from under the rubble. A gray cloud of dust fills a street, and people cover their mouths as they run away.
The group, also known as the White Helmets, has received global praise for its rescue operations in rebel-held areas in Syria.
Pro-government media and the Observatory said two people were killed when insurgents shelled government-held areas in Aleppo city.
Violence in Syria has escalated as an internationally backed cease-fire that took effect in late February has broken down in recent days, with the government and rebel groups trading blame. In the past week, nearly 200 people have been killed in Syria, straining the agreement, which was brokered by the U.S. and Russia.
The U.N. envoy for Syria will brief the Security Council after the latest round of peace talks in Geneva. The opposition backed out of the talks last week, saying the government had violated the cease-fire repeatedly. U.N. envoy Staffan de Mistura met with the Syrian government delegation Tuesday, and this round of talks was to conclude today.
U.N. Secretary-General Ban Ki-moon told reporters in Vienna he was "deeply concerned about developments on the ground" in Syria, saying de Mistura and others "are working very hard to keep the cessation of hostilities on track."
Meanwhile, Turkey's foreign minister said the United States will deploy a rocket-launcher system in southeastern Turkey across the border from Syria as part of a joint effort to combat the Islamic State extremist group.
In an interview with the Haberturk newspaper published Tuesday, Mevlut Cavusoglu said a U.S. High Mobility Artillery Rocket System would arrive in May.
Turkey has regularly shelled Islamic State targets in northern Syria in response to cross-border rockets which have hit the Turkish city of Kilis. Turkish shells have a range of approximately 25 miles, while the U.S. missiles can reach targets 55 miles away.
"In order to clear the area of Daesh, we have to give the moderate opposition both aerial and ground support," Cavusoglu said, using an Arabic acronym for the Islamic State. Clearing the Manbij area would pave the way for the creation of a "safe zone," he said.
Turkey has long advocated for the creation of a buffer zone in Syria but has failed to get its allies on board. Turkey is part of the U.S.-led coalition against the Islamic State and hosts 2.7 million Syrian refugees.
A Section on 04/27/2016