article_snippet: The citadel (background) in the northern Syrian city of Aleppo was where 34 people were killed yesterday when Al Qaeda-backed rebels set off a powerful tunnel explosion targeting an intelligence HQ .
article_snippet: Watching the destruction: Members of Syrian opposition forces are seen hiding behind rubble after Members of Syrian opposition forces blow up the tunnel beneath the Syrian Air Intelligence Directorate's Aleppo branch .
article_snippet: Yesterday's terror attack began with a huge blast from explosives in a tunnel near the building, the Observatory and a Syrian military source said. '
article_snippet: Gunmen blew up a tunnel that Gunmen dug (into the regime-controlled sector) and then attacked the area surrounding the air force intelligence headquarters,' a Syrian military source said.
article_snippet: Journalists in eastern Aleppo said a huge blast from explosives was heard across the northern Syrian city of Aleppo.
article_snippet: A member of the Syrian opposition force is seen after blowing up the tunnel under the intelligence HQ .
article_snippet: Smoke rises after Syrian opposition forces blow up the Syrian Air Intelligence Directorate's Aleppo branch .
article_snippet: Carnage: the Syrian Air Intelligence Directorate's Aleppo branch is seen going up in smoke after Yesterday's terror attack .
article_snippet: Rebels from several factions then launched on assault on the building, part of which had collapsed from a huge blast from explosives, said the Observatory, which relies on a network of sources inside Syria.
article_snippet: Al-Qaeda's affiliate in Syria, Nusra Front, said on Twitter that Al-Qaeda's forces, along with other rebel factions, had 'stormed the air force intelligence offices and surrounding buildings'.
article_snippet: Yesterday's attack targeting air force intelligence offices is understood to have been carried out by members of the Al Qaeda-affiliated terror group Nusra Front (pictured)
article_snippet: Blast: Civilians and civil defense members run past flames and smoke rising from a site hit by what activists said was a barrel bomb dropped by forces loyal to Syria's President Bashar al-Assad in Aleppo this morning .
article_snippet: Flames: A civil defence member  puts out a vehicle fire caused by a Syrian regime barrel bomb today .
article_snippet: Wednesday's attack featured a favoured tactic of Syria's rebels -- especially in Aleppo -- of digging tunnels near government buildings and setting off explosives.
highlights_snippet: The detonated explosives buried in a tunnel beneath an intelligence HQ .
  