DUSHANBE, Tajikistan: Russian Foreign Minister Sergei Lavrov on Thursday hit out at the United States for "blasphemous" accusations blaming this week's blasts in the city of Aleppo on the Syrian regime.

"Yesterday I saw a semi-neutral report on CNN that it was not ruled out that this terrorist act had been staged by the government forces themselves," Lavrov said in the Tajik capital Dushanbe.

"I cannot imagine anything more blasphemous."

Earlier this week two blasts tore through an Aleppo campus while students were writing exams, killing at least 87 people. No one has claimed responsibility for the blasts but the government and rebels have blamed each other.

In a statement on Wednesday, the Russian foreign ministry blamed "terrorists" for the "merciless bloody provocation."

It said the explosions were "the terrorists' revenge for the significant losses sustained in their confrontation with government forces."

But the United States on Wednesday said the blasts were caused by the regime unleashing air strikes on the university buildings.

"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.

Lavrov also reiterated Thursday Russia's stance that Moscow was against referring Syria to the International Criminal Court to investigate war crimes accusations.

"We should answer the question: what is more important for us?" Russia's top diplomat told reporters. "If the most important for us is to punish someone, to condemn someone, to put someone on trial, then it's one logic."

"If the most important is to stop the violence, then I would focus on the actions aimed at this. Everything else can wait."