The truce in Syria in force since midnight on Feb. 27, has already been marred by airstrikes and artillery attacks.

Airstrikes hit insurgent-held areas in the provinces of Aleppo, Hama and Idlib, according to videos posted online by insurgent groups and NGOs. They were attributed to the Syrian government or its Russian allies, reports the New York Times.

Trading charges, Russian officials claimed nine violations by opposition groups and Turkish allies in the first 24 hours of the truce, including shelling attacks on Damascus and Turkish artillery fire across into Tal Abyad, reports the New York Times.

"We have violations here and there, but in general it is a lot better than before and people are comfortable," said Salem al-Meslet, spokesman for the Saudi-backed High Negotiations Committee which wants the truce to "last forever" and said that it was the "responsibility of the United States to stop any violations," reports the AFP.

Speaking to CNN, Meslet detailed that the Syrian regime had committed 15 violations. "We worry (Syrian President Bashar al-Assad) will increase the violations if no one says anything to him," Meslet said, according to CNN.

The High Negations Committee is appraising the United Nations and members of the International Syria Support Group - except for Russia and Iran -in writing, about the cease fire violations.

"Setbacks are inevitable. Even under the best of circumstances, we don't expect the violence to end immediately. In fact, we are certain that there will continue to be fighting, in part because of organisations like ISIL (Islamic State) and Al-Nusra," a senior U.S. administration official told the AFP.