The attack is the second of its kind in a week, and comes just over a month after rebels lost their bastion in the heart of Homs city to regime control.
The Syrian Observatory for Human Rights said at least six people were killed in the attack and nine seriously wounded, adding that it expected the death toll to rise.
State television put the death toll at three, and said women and children were among the nine wounded in what it called a "terrorist car bomb attack in the Akrameh district.
Homs was once dubbed "the capital of the revolution" against President Bashar al-Assad. Most of the city, except the battered district of Waar, has returned to regime control after two years of bombardment and siege.
Elsewhere, warplanes launched 25 air strikes on Mleiha southeast of Damascus, a key rebel bastion that the regime has struggled for weeks to recapture, the Observatory said.
Regime ground forces also fired surface-to-surface missiles at the Mleiha as troops backed by Lebanon's Shiite Hezbollah battled rebels and their jihadist Al-Nusra Front allies, said the monitor.
Meanwhile, activists in the rebel-held Al-Hajar al-Aswad neighbourhood in southern Damascus accused the regime of cutting off water supplies for more than two weeks.
"Some 20,000 people live here, mostly women and children. The regime wants to pressure civilians into forcing rebels to sign a truce with the army," activist Rami al-Sayed told AFP.
"People are suffering from inflammations and digestive system diseases because they are drinking dirty water from wells," he added.
On another front, an armed group allied to the jihadist Islamic State of Iraq and the Levant (ISIL) on Wednesday kidnapped two Syrian rebel commanders in Deir Ezzor province.
While rebels seeking Assad's ouster initially welcomed ISIL among their ranks, the jihadists' systematic abuses turned the opposition against them.
You’ve reached your limit of 10 free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app