Two Islamic judges were wounded in an explosion targeting the Palace of Justice (Dar al-Adl) in the southern province of Daraa, activists said on Wednesday.
The blast comes amid renewed clashes between an Islamic State (ISIS)-linked group and southern rebels.
Earlier on Tuesday, a suicide bomber blew himself up inside a base belonging to the Free Syrian Army-affiliated Mutazz Billah Army in the town of Mzairib in the western countryside of Daraa, killing one fighter, local activists reported.
Activists said the suicide bomber had links to ISIS militants.
Israeli airstrikes on the town of Saham al-Jolan are reported to have killed 10 fighters from the Khalid bin al-Walid Army, which has pledged allegiance to ISIS, along with two other women believed to be the wives of fighters, the Britain-based Syrian Observatory for Human Rights said.
The Observatory said the Khalid bin al-Walid Army is estimated to have some 1,200 fighters, and controls territory in Daraa along the border with the Isreali-occupied Golan Heights.
This article was edited by The Syrian Observer. Responsibility for the information and views set out in this article lies entirely with the author.