Multiple bombings targeted a government-run security checkpoint in the central Syrian city of Homs on Tuesday, killing at least 20 people, Syria's state-run news agency reported.
The attack, which was claimed by the Islamic State group, came as government forces retook a strategic town from opposition fighters and militants in the south of the country.
Homs Governor Talal Barazi told the SANA news agency that the checkpoint was hit "first by a car bomb, which was then followed by a suicide bombing."
The Islamic State group claimed responsibility, according to a report by the Aamaq news agency, which is affiliated with the extremist group.
Syrian state television broadcast footage of the aftermath of the Homs bombing, showing extensive damage to shops and apartments around the site of the explosion in the Zahra neighborhood, which is inhabited mostly by members of President Bashar Assad's Alawite sect, an offshoot of Islam.
The Britain-based Syrian Observatory for Human Rights, an opposition group which relies on a network of informants across Syria for its news, said the death toll had climbed to 25, with 15 of the casualties being security personnel.
The Observatory said witnesses at the scene said the first bomber attracted a crowd by shouting curses about the Homs governor, then blew his vehicle up.
Homs, which was once known as the "capital of the revolution," is Syria's third largest city and was one of the first to rise against the government in 2012. Government forces have since managed to expel most militants from the city and much of it has been destroyed.
Meanwhile, in southern Syria, government forces took control of the town of Sheikh Meskin, culminating an offensive that began in late December to retake the town after seizing the Brigade 82 military base, nearby.
Sheikh Meskin lies near the highway connecting Damascus and the Jordanian border and connects the Syrian capital to Daraa, a border town held by opposition fighters.
Heavy fighting has continued outside the town, between forces loyal to the government and opposition fighters, supported by al-Qaeda's Syrian affiliate, the Nusra Front.
The Observatory reported Russian and Syrian air strikes were supporting the offensive.