Syrian artillery gunners shelled a bread bakery full of workers and customers on Tuesday in an insurgent-held neighborhood of Aleppo, Syria’s largest city, killing at least 20 people and wounding more than 30 in what activists and videographers described as a sudden and devastating attack.
The shelling at Al Zura Bakery was among the more graphic episodes of violence to hit Aleppo and the capital, Damascus, on Tuesday, casting further doubts on the already dim prospects of a nationwide cease-fire for the coming Eid al-Adha holiday, which the newly appointed peace envoy from the United Nations and Arab League, Lakhdar Brahimi, has been trying to negotiate for the past week.
Disturbing video uploaded to the Internet, which appeared genuine but could not be corroborated independently, showed what was described as the aftermath of the bakery shelling in Aleppo’s Hanano district, with mangled bodies interspersed with upended loaves of freshly baked pita on the bakery’s bloodied floor, as screaming rescue workers hauled the dead and wounded to waiting pickup trucks and taxicabs. Some of the victims were children.
Abu al-Hasan, an activist from the Aleppo suburb of Maree, said in an interview that most of the dead were bakery workers. He said it was unclear whether the attackers had been aiming for the bakery.
‘‘The problem is those kinds of missiles are not guided to their intended targets,’’ he said. ‘‘They’re not precise. They fall on random buildings.’’
He said the shelling came as residents of the neighborhood, who had been too afraid to venture outside for the past few days, finally took the risk in order to buy food for Eid al-Adha, a widely celebrated Muslim holiday that starts Friday.
Aleppo, near Syria’s northern border with Turkey, has been under siege for three months and has become a focal point of the insurgency against President Bashar Assad. Rebels have frustrated attempts by Syrian forces to retake the entire city and have threatened to cut off the military’s supply lines there.
At the same time, bakeries in rebel-held areas of Aleppo have emerged as vitally important resources that are clearly potential targets for Syrian forces seeking to starve insurgents and their sympathizers into submission.
The bakery attack came as Brahimi, a veteran Algerian statesman who became the special Syria peace envoy last month, left Syria after having met with Assad and his subordinates over the weekend.
A statement issued by the United Nations said Brahimi had held ‘‘frank and substantive’’ discussions with Assad, who had ‘‘given a positive reaction to his call for the government to declare a military pause during the Eid al-Adha holiday.’’
But there was no official announcement of such a truce. Many Syrian activists and opposition figures had said it was highly unlikely anyway, given what they called Assad’s complete lack of credibility and the inability of Brahimi’s predecessor, Kofi Annan, to broker a pause in the fighting.
Brahimi had said he hoped that a religiously inspired truce would be the basis for at least the start of a dialogue between antagonists in the 19-month-old conflict, which has left more than 20,000 people dead. He is to brief the Security Council by video link from Cairo on Wednesday, said Martin Nesirky, a UN spokesman.
In Geneva, the UN refugee agency reported Tuesday that the number of Syrians who have fled to neighboring countries to escape the conflict had climbed to more than 358,000 and that Lebanon had become the third country, following Turkey and Jordan, to house more than 100,000 Syrian refugees.
Melissa Fleming, a spokeswoman for the refugee agency, said the sectarian mayhem in Lebanon caused by a bombing in Beirut on Friday had temporarily disrupted the agency’s registration work in Lebanon.
Meanwhile, the Associated Press reported that Syrian warplanes on Tuesday struck a strategic rebel-held town in the country’s north in an attempt to reopen a key supply route.
On Tuesday, government aircraft attacked Maaret al-Numan and the village of Mar Shamsheh, as troops and rebels battled over a nearby Syrian military camp that has been under siege for days, according to the Britain-based Syrian Observatory for Human Rights. The activist group reported more than two dozen casualties among the rebels.
Opposition fighters seized Maaret al-Numan, which lies along the main highway between Aleppo and Damascus, earlier this month. Their presence has disrupted the regime’s ability to send supplies and reinforcements to the northwest. This has hampered the government’s fight in Aleppo.
Amateur video posted Monday showed rebel fighters unleashing heavy bursts of machine-gun fire, apparently at a convoy heading to the besieged army camp. Syria restricts access to foreign reporters and the authenticity of the video could not be confirmed.
An international human rights group, meanwhile, said the Syrian air force stepped up attacks with cluster bombs in the past two weeks, dropping more over a wider area, despite Damascus’ denials that it has used the widely banned munitions, according to the Associated Press.
The New York-based Human Rights Watch, citing amateur videos and interviews with victims, residents, and activists, said it has received new information about more than 35 sites where cluster bombs were dropped.