The man was thrown to the ground in the force of the blast before crawling away on his hands and knees
This shocking clip captures the dramatic aftermath of a man throwing his cigarette butt down an underground sewer.
At the start of the CCTV footage, a smartly dressed man is seen walking up to the hole in the floor.
He begins to pour what appears to be a bag of rubble into the crevice.
Shortly, another man approaches the hole and begins to peer in.
Totally unaware of the danger to come, he then throws a cigarette butt into the gap, before preparing to walk away.
As he begins to turn away, the pavement violently explodes in his face, throwing his whole body to the ground.
Believed to have happened on a street in Tehran, Iran, the footage shows concrete hurtling towards the camera.
As the view clears, the man can be seen lying amongst debris on the floor.
He then begins to crawl away on his hands and knees, before scrambling to his feet and walking away.