The blasts, one from a car bomb and another from a suicide attack, struck the Zahra district in the middle of the city, said the Britain-based Observatory, which monitors the conflict through a network of contacts on the ground.
Syria’s state news agency SANA reported two car bomb blasts, but gave a lower initial toll of six dead and 37 wounded.
It was the second major attack in the city since a ceasefire deal took effect earlier this month, paving the way for the government to take over the last rebel-controlled area of Homs.
Twin blasts on Dec. 12, also in Zahra, killed at least 16 people. Islamic State claimed reponsibility for that attack, saying it had detonated a suicide car bomb.
Under the Homs ceasefire deal, at least 700 insurgent fighters and members of their families left the last rebel-controlled area of the city, al Waer district. The United Nations presided over implementation of the deal.