State TV said the local head of military intelligence was among the dead. Some reports put the death toll at more than 40.
The jihadist group Tahrir al-Sham said it carried out the attacks.
Homs has been under government control since December 2015 when rebels left under a ceasefire deal.
The Syrian Observatory for Human Rights, a monitoring group, said attackers targeted the headquarters of military security in the city and also a branch of state security.
The attacks took place in the heavily guarded Ghouta and Mahatta districts.
State TV said provincial army intelligence chief General Hassan Daabul, a close associate of President Bashar al-Assad, was among the dead.
Tahrir al-Sham said five of its fighters had taken part in the assault.
The group was formed when Jabhat Fateh al-Sham, known as the Nusra Front until it broke off formal ties with al-Qaeda last July, merged with four smaller Syrian factions.
Earlier this month it announced that its leader was Hashim al-Sheikh, who previously served as head of the powerful Islamist rebel group, Ahrar al-Sham.