A bomb blast hit a passenger van on a street in Al Zahra neighbourhood in the regime-held city of Homs, Syria, at noon on Wednesday. At least five people were killed and six wounded, Syrian state news agency SANA quoted the Homs health director as saying.
The Syrian Observatory for Human Rights confirmed the fatalities.
SANA said the attack was carried out by militants.
Analysts have predicted that militant elements within the rebels fighting to oust regime leader Bashar al Assad will increasingly turn to guerrilla-style attacks in territory controlled by the government after suffering military reverses.
Regime-held cities have been hit by a series of bombings in recent weeks, including in Homs. A gun and bomb attack killed dozens of people in February, including a senior security official.
Scores of people were killed in suicide attacks in the capital Damascus earlier this month. This included twin bombings on March 15 at a central courthouse and a restaurant, and a blast days earlier near an important shrine frequented by Shia Muslims.