The deadly attacks, in which suicide bombers blew themselves up in vehicles, targeted two towns in Hama province that are majority Alawite, the religious community to which President Bashar al-Assad belongs.
The first bombing, in the town of Jibrin, in the southwest of the province, killed 17 civilians, including the 11 children, state media said.
The second attack hit the town of Al-Humairi and killed one person, state news agency SANA reported.
They come after a double car bombing claimed by al-Qaeda's Syria affiliate al-Nusra Front killed at least 100 people on Tuesday in a majority Alawite district of the central city of Homs.
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This week also saw 33 civilians killed in the main northern city of Aleppo on Thursday when government aircraft bombed a popular market in a rebel-held district.
Despite the violence, Syria's government plans to hold the country's first multi-candidate presidential elections in just over a month's time on June 3.
But 23 other hopefuls have also submitted applications to stand, although only Assad and a maximum of two other candidates are expected to secure sufficient backing in parliament to get their names on the ballot.
The Supreme Constitutional Court is expected to announce which candidates have made the cut on May 6.
The government has not explained how it will organise countrywide elections with violence that has killed more than 150,000 people ravaging much of Syria.
The conflict in Syria began in March 2011, with peaceful anti-government protests that the regime tried to put down with force.
Much of the opposition took up arms and the country has since sunk into a civil war that has proved impervious to international mediation efforts.
Since early January, moderate and Islamist rebels, along with Al-Nusra Front, have also been battling against the jihadist Islamic State of Iraq and the Levant (ISIL).
The group has gained notoriety for abuses against both civilians and rival opposition fighters.