BEIRUT — A government airstrike on a bakery in a rebel-held town in Syria killed more than 60 people on Sunday, activists said, casting a pall over a visit by the international envoy charged with negotiating an end to the country’s civil war.
The strike on the town of Halfaya left bodies and debris up and down a street, and more than a dozen dead and wounded people were trapped in tangled heap of dirt and rubble.
The attack appeared to be the government response to a newly announced rebel offensive seeking to drive the Syrian Army from a constellation of towns and villages north of the central city of Hama. Halfaya was the first of the area’s towns to be ‘‘liberated’’ by rebel fighters, and activists saw Sunday’s attack as payback.
‘‘Halfaya was the first and biggest victory in the Hama countryside,’’ said Hama activist Mousab Alhamadee via Skype. ‘‘That’s why the regime is punishing them in this way.’’
The total death toll remained unclear, but the Britain-based Syrian Observatory for Human Rights said more than 60 people were killed. That number is expected to rise, it said, because some 50 of those wounded in the strike were in critical condition.
Amateur videos posted online Sunday showed residents and armed rebels rushing to the scene.
More than a dozen dead or seriously wounded people lay in the street near a simple, concrete building. Rebels screamed in distress while trying to extract the bodies, while others carried away the wounded.
The bakery was one of three in Halfaya that had been closed for days because of a lack of flour. On Sunday, it was mobbed with people after word that a shipment of flour had arrived from Turkey. Witnesses said at least three bombs fell near the building.
It was unclear from the videos whether the bakery was the intended target. Nearly all the dead and wounded appeared to be men. Some wore camouflage, raising the possibility that the jet had targeted a rebel gathering.
For the past week, rebels have been launching attacks in the area, most notably in the nearby village of Morek, where they hope to seize control of the country’s main north-south highway, preventing the regime from getting supplies to its forces further north in the provinces of Idlib and Aleppo.
On Saturday, one rebel group threatened to storm two predominantly Christian towns nearby if their residents did not ‘‘evict’’ government troops they said were using them as a base to attack nearby areas.
The activist accounts could not be independently verified due to restrictions on reporting in Syria. The Syrian government does not respond to requests for comment on its military activities.
The attack coincided with the start of a two-day visit by Lakhdar Brahimi, who represents the UN and the Arab League, to meet with top Syrian officials. Brahimi has made little apparent progress toward ending Syria’s crisis since assuming his post in September, mostly because the sides appear more interested in fighting than in sitting down for talks.
Brahimi did not speak publicly upon arriving in Damascus for a two-day mission, and it was unclear whether he would present new ideas to end the war. His trip appeared troubled from the start.
Instead of flying directly to Syria as he had on previous visits, Brahimi landed in Beirut and traveled to the Syrian capital by land because of fighting near the Damascus airport, Lebanese officials said.
The Lebanese officials, who spoke on condition of anonymity because they were not authorized to brief reporters, said Brahimi was expected to meet Syria’s foreign minister later Sunday and President Bashar Assad on Monday.
The trip is Brahimi’s third since taking the job following the resignation of former UN secretary general Kofi Annan after both sides disregarded a cease-fire he brokered in April.
While not advancing a comprehensive peace plan, Brahimi has called on the sides to negotiate a solution.
The security situation has gotten worse for the regime since his last visit, with rebels storming military bases and seizing valuable munitions. Russia, Assad’s most powerful international backer, also appears to have changed its assessment of Assad’s strength, as top officials say they do not seek to preserve his regime, while still calling for a negotiated solution. Still, neither side appears willing to talk.
Violence raged elsewhere in the country. Antiregime activists reported government airstrikes on suburbs east of the capital and the northern province of Aleppo. Airstrikes on the town of al-Safira, south of Aleppo, killed 13 people, including a mother and five daughters from one family, a local activist named Hussein said via Skype.
The Observatory said at least 10 rebels and an unknown number of government troops were killed in clashes in Afreen, near Aleppo as rebels sought to storm an army base there.