More than 50 people were wounded in the attack in al-Horra, SANA said, blaming the attack on rebels fighting to overthrow President Bashar al-Assad.
"Terrorists exploded a truck loaded with a large amount of explosives," SANA quoted a policeman as saying. "It is estimated that the explosives weighed three tonnes."
The Islamic Front, a rebel coalition, claimed responsibility for the attack. It said on Twitter that a radio-controlled bomb had targeted a "gathering of Assad militia."
The Syrian Observatory for Human Rights said 38 people were killed, most of them civilians including women and children, as well as security personnel. It also said more than 40 were wounded.
On Thursday, a car bomb exploded in the city of Homs, to the south of Hama.
The Observatory updated its toll for that attack, saying at least 14 people were killed, including 10 civilians, in a neighbourhood populated by Alawites, the Islamic sect to which Assad belongs.
No one claimed responsibility for what was the second attack in Homs - Syria's third largest city - in less than a week, but state television blamed it on rebels.
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