"Moscow strongly condemns the inhumane terrorist attacks," which killed at least 150 people, the ministry said in an online statement. "We express our sincere condolences to the families of those killed and wish a speedy recovery to the injured."

It urged the international community to make "proper principled responses" to the terrorist acts.

It is important to effectively thwart further attempts of the Islamic State (IS), the Nusra Front and other terrorist groups, which are betting on further aggravation of the situation in Syria and the whole region, to further incite sectarian strife, the statement said.

"The brutal crimes of extremists aim to intimidate the civilian population, undermine efforts to achieve a lasting political settlement of the Syrian crisis in the interests of all Syrians, as well as efforts to end the violence and bloodshed," it said.

Five deadly bombings killed at least 150 people in central and southern Syria on Sunday, marking one of the highest death tolls in a single day during the years of conflict. The IS has claimed responsibility for the bombings.

The serial terrorist attacks happened as world powers were pushing for a truce in Syria in line with the agreement reached on Feb. 12 during an International Syria Support Group meeting.

Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry made three phone calls on Sunday to discuss details of the modalities for the cessation of hostilities in Syria.

Proposals and options for a ceasefire have been submitted for consideration by Russian President Vladimir Putin and his U.S. counterpart, Barack Obama, the Russian Foreign Ministry said.

Kerry on Sunday confirmed that a deal between the United States and Russia was reached over the truce in Syria and that a ceasefire agreement is likely to be announced very soon as well.