The attacks took place in and around the government-held city of Sweida, state media and monitors reported. The Islamic State group is believed to be behind the violence.
At least another 30 people were wounded, said the Syrian Observatory for Human Rights, a monitoring group.
The Syrian government has retaken control of much of southern Syria in recent months.
State news agency Sana reported one suicide attack in Sweida and said security forces chased and killed two other attackers before they could blow themselves up. Militants also attacked three villages north-east of the city. it said. The report gave no casualty figures.