UN Secretary-General Antonio Guterres has "unequivocally condemned" a deadly attack on a mosque in Syria’s central city of Homs, stressing that attacks on civilians and places of worship are unacceptable.

In a statement on Friday, Guterres said those responsible for the attack must be identified and held accountable, according to his spokesman Stephane Dujarric.

"Attacks against civilians and places of worship are unacceptable," Guterres said, adding that accountability was essential.

He noted that Syrian authorities had denounced the attack and reaffirmed their commitment to combating terrorism.

"The Secretary-General extends his condolences to the families of those killed and expresses his sympathy to all those injured, wishing them a prompt and full recovery," Dujarric said.

At least eight people were killed and 18 others injured in the attack at the Imam Ali ibn Abi Talib Mosque on Al-Khodari Street in the Wadi al-Dhahab neighbourhood of Homs.

The incident comes as Syria’s new administration seeks to tighten security nationwide and pursue remnants of the former regime accused of stirring unrest.