Deadly suicide bombing hits Damascus courthouse: state TV

The suicide bomber detonated his explosives' vest inside the main judicial building in the capital of Damascus, Syrian state TV reported.

"A terrorist blows himself up inside the old palace of justice in Damascus and there are dead and wounded," state television said in a breaking news alert.

Official reports placed the initial death toll at 25, adding that at least 45 people were wounded.

The Judicial Palace is near the famous and crowded Hamidiyeh market in Damascus.

The blast follows twin attacks on Saturday that killed at least 40 people in the Syrian capital.

That attack was claimed by the Syria's ex al-Qaeda affiliate, formerly known as the Nusra Front.

There was no immediate claim for Wednesday's bombing, which coincides with the sixth-year anniversary of the Syrian war.

The Syrian conflict began six years ago, when the Baath regime - in power since 1963 and led by Bashar al-Assad -responded with military force to peaceful protests demanding democratic reforms during the Arab Spring wave of uprisings, triggering an armed rebellion fuelled by mass defections from the Syrian army.

According to independent monitors, hundreds of thousands of civilians have been killed in the war, mostly by the regime and its powerful allies, and millions have been displaced both inside and outside of Syria.

The brutal tactics pursued mainly by the regime, which have included the use of chemical weapons, sieges, mass executions and torture against civilians have led to war crimes investigations.