More than 80 people are dead after twin blasts at a university campus in Syria's largest city.
A U.K.-based Syrian opposition group told Al Jazeera that 83 people were killed and more than 150 were wounded in the explosions near the university's dorm in Allepo.
The government and opposition blamed each other for the blasts. According to The Associated Press, rebels blamed the Assad regime for carrying out airstrikes; state-run media said the rebels fired rockets at the campus.
"Aleppo's university is in the city's northwest, a sector controlled by government forces, making it unclear why government jets would target it, as opposition activists claim," the AP reported.
But the news agency added: "The scale of destruction in videos shot at the site, however, suggested more powerful explosives had been used than the rockets the rebels are known to possess."
The Syrian regime prevents most foreign media from operating inside the country, making independent verification of attacks and casualties difficult.
As NPR's Kelly McEvers and Rima Marrouch reported Monday on Morning Edition, rebels control nearly 60 percent of Aleppo, some six months after they tried to storm the city; the government controls the rest.
Tuesday's blast ends a mostly uneasy calm in Aleppo. As Kelly and Rima reported, "Although there's not much fighting here anymore, government soldiers sometimes try to pick off rebel fighters or civilians who cross from one side to another."
Here's more from their story:
"Right now this cold front line is a lot like the fight for Syria: Both sides think they can win, but neither side is winning, so neither side is going to back down.
"In recent months, rebels have realized that fighting for inches along these front lines is no way to win a war. So while a small number of fighters hold the front, the rest have turned their attention to government air bases that ring the city.
"Rebels believe if they can cut off the government's ability to resupply its troops, Aleppo will fall."
The U.N. says more than 60,000 people have been killed in Syria's civil war that began in 2011 with protests calling for political reforms.