Syria war: Aleppo tunnel bomb 'kills 38 government troops'
Dozens of pro-government troops were killed when rebels blew up a tunnel underneath a building in the Syrian city of Aleppo, reports say.
A UK-based monitoring group said 38 troops died in the blast, which it said happened on Thursday.
The Thuwwar al-Sham rebel group posted a video online that appeared to show a building used by government troops being destroyed by a huge blast.
Aleppo is divided between the rebel-held east and government west.
Hundreds of thousands of people live in the east of the city, which was effectively cut off by government forces earlier this month.
Government forces backed by Russian air strikes have intensified their military campaign against the city's rebel-held areas in recent weeks.
The city has been divided between the two sides for the past four years.
Footage by Thuwwar al-Sham purported to show members of the group planting explosives inside the tunnel. The video then showed a building blowing up in a huge explosion in a cloud of rubble and ash.
The Syrian Observatory for Human Rights (SOHR) initially said that the death toll from the tunnel bomb was 14, but revised this upward on Friday.