The blast rocked a checkpoint on the eastern entrance of the Salamiyah town on Saturday, the official SANA news agency reported.
Two civilians were among those killed in the bombing.
A militant group affiliated with the Takfiri Daesh terrorist group has claimed responsibility for the explosion, according to reports.
The so-called Syrian Observatory for Human Rights also held Daesh responsible for Saturday’s bomb blast.
“The car bomb attack is not a breach to the truce because it occurred in an area where the cessation of hostilities agreement does not apply,” said Rami Abdulrahman, head of the monitoring group.
A second explosion was also reported in the same area, where an explosives-laden motorbike went off. An unspecified number of people were injured in the incident.
Salamiyah is considered as a frontline in battles between Syrian government forces and Daesh Takfiri militants.
The deadly incident came hours after a two-week ceasefire brokered by Russia and the US went into effect in Syria, urging the “cessation of hostilities” by the warring sides to the conflict gripping the Arab country.
The Damascus government and 97 opposition and militant groups said they will respect the truce, which does not apply to Daesh and the al-Qaeda-affiliated al Nusra-Front.
Staffan de Mistura, the United Nations special envoy for Syria, said he plans to resume the indirect peace talks between the Syrian government and opposition on March 7 on the condition that they observe the ceasefire.
He announced a halt in the peace talks on February 3 after the opposition refused to continue the discussions in the wake of Syrian army gains.
The foreign-sponsored conflict in Syria, which started in March 2011, has claimed the lives of some 470,000 people and left 1.9 million injured, according to the Syrian Center for Policy Research; Press TV reported.
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