At least 15 people were killed and 64 injured as a suicide car targeted al-Zahraa neighborhood which is inhabited by a majority of Alawite, the London-based Syrian Observatory for Human Rights (SOHR) said on Saturday.
SOHR activists observed a truck loaded with humanitarian aids entering al-Waer neighborhood included in the truce of al-Waer.
Homs was a centre of the uprising against Syrian President Bashar al-Assad that started in 2011. The blast comes two days after the implementation of a truce deal in Waer, another district of Homs on its northwestern outskirts.
Under that deal, agreed between the local government and insurgents under the auspices of the United Nations, a number of fighters and civilians left Waer, the last insurgent-held area of Homs, and humanitarian aid was allowed in.
The agreement, which is still being implemented in stages, allowed the government to tighten its control of the city.