The large offensive is backed by the Lebanese Shi’ite group Hezbollah and initially made swift progress before slowing. The gains, made on Friday and Saturday, mark a new push in the government campaign.
Syria’s state news agency SANA said the village of Tal Al-Majda in Sweida province and Tal Antar in Deraa were taken. Both are near Jordan.
The south is the last notable foothold of the mainstream, non-jihadist opposition to President Bashar al-Assad, who has consolidated control over much of western Syria after almost four years of civil war.
Al Qaeda’s Syrian arm, the Nusra Front, is also active in the south and has clashed with western-back rebels. Rival Islamic State jihadists control much of the north and east of the country.
The offensive aims to shield the capital Damascus, a short drive to the north. The insurgents had made significant gains in the south in recent months, taking several military bases.
Hezbollah, a powerful Shi’ite Islamist group backed by Iran, has offered crucial military support to the Syrian government during the civil war, which has killed around 200,000 people.