Watch for the explosion.
It happened Thursday in Syria's second city, Aleppo.
That's where rebels say they detonated a huge bomb beneath a hotel used by forces loyal to President Bashar al-Assad.
The rebel group called the Islamic Front claimed responsibility.
It posted these videos of the blast online, which Reuters cannot independently verify.
The Islamic Front says 50 soldiers were killed in the blast, but doesn't say how it got that number.
A UK-based monitoring group, which tracks violence in Syria using sources on the ground, says at least 14 members of the security forces were killed.
State TV showed the incredible damage at the site where the Carlton Hotel once stood.
Both state TV and the monitoring group said other buildings were also damaged.
This is the edge of the city's medieval citadel.
State TV said nearby buildings were rich with antiquities but gave no details of casualties.
