Syrian rebels destroy regime building with massive tunnel bomb

Syrian rebel fighters detonated an underground bomb on Thursday morning, which collapsed a former public building in central Aleppo said to function as a military base for regime troops.

Rebel sappers dug a tunnel beneath the regime baracks in the centre of Aleppo before rigging it with explosives and detonating the bomb.

The Thuwar al-Sham rebel group - which operates mainly in Aleppo's western countryside - released a video showing the blast.

"We are now inside the underground tunnel which will be destroyed shortly," a Syrian fighter said in the video before the attack.

"We are under the regime's traffic directorate building, which is an important site for the Assad regime and his allies."

The group promised more similar strikes until "the complete liberation" of Syria.

The video, which circulated online, showed the powerful explosion bringing down the entire building.

Dozens of regime fighters were killed in the attack, the group said.

Rebels have used similar tunnel bombs to attack regime bases in Aleppo and other areas.