There was no immediate claim of responsibility.
In a village just outside Homs, two other people were killed by artillery shelling, including a baby girl, the Observatory said.
Homs has been a frequent battleground in the 20-month rebellion aimed at toppling Assad.
The increase in bombing attacks as part of the civil war has raised concerns that Islamist extremist groups are taking a larger role on the side of the rebels.
SANA claimed that on the outskirts of Homs, the Syrian army killed scores of rebels in an attack on their hideouts.
Activists say at least 40,000 people have been killed in the conflict, which began with peaceful pro-democracy protests but turned into a civil war.
While fighting has intensified nationwide in the past weeks, members of the new Syrian opposition leadership coalition held talks in Egypt on a transitional government.
The Syrian National Coalition for Opposition and Revolutionary Forces was established earlier this month in Qatar under pressure from the United States for a stronger, more united opposition body to serve as a counterweight to the more extremist forces which have joined the fight against Assad's regime — some of them foreign jihadists.
The coalition members said they have agreed on the framework of a transitional government with 10 ministers. Walid Albunni, the coalition's spokesman, said its members will speed up the decision-making process and name the prime minister in the coming days to keep up with developments on the ground.
“We have to work as fast as possible to be ready for the downfall of the regime,” Albunni said Saturday at the end of a three-day meeting in Cairo, where the opposition body is based.
Albunni said the coalition could support a United Nations peacekeeping force in Syria, but only after Assad is toppled.
“Anything can happen after all those who have stained their hands with blood of people are gone,” Albunni said.