The United States on Wednesday condemned the "despicable attack" on university buildings in the Syrian city of Aleppo, blaming the regime for unleashing air strikes that killed at least 82 people.

"The United States is appalled and saddened by the Syrian regime's deadly attack yesterday on the University of Aleppo," State Department spokeswoman Victoria Nuland said, adding most of the victims were students and refugees.

"According to eyewitnesses at the scene, regime planes launched aerial strikes on university facilities," she told journalists.

"We condemn this despicable attack on unarmed civilians and continue to emphasize that those responsible for unlawful killings and other violations of international law will be identified and held accountable."

The United States also sent its "sympathies and condolences... to all those devastated by this senseless tragedy."

"The Syrian people have already endured too much loss as a result of the Assad regime's relentless attacks on its own people," Nuland added.

The twin blasts ripped through the university buildings in Syria's second city Aleppo on Tuesday, in attacks which the Syrian regime of President Bashar al-Assad blamed on opposition rebels.

State news agency SANA said "it was the first day of exams. Students and displaced people were among the victims."

As well as students, the university campus houses some 30,000 people who have fled parts of the city ravaged by fighting since rebels seized many neighborhoods last July.