Heavy, dark smoke fills the air as we arrive early in the morning to witness the damage wreaked by the devastating explosion caused by a runaway train loaded with chemicals and fuel near the north-eastern city of Neyshabur on Wednesday.
Everything is covered in a yellow powder. People are coughing along with the monotonous sound of the bulldozers working to find missing victims.
We are wearing double face masks but it doesn't help. The thick smoke still gets into our lungs and we have to run away from the worst areas of this field of death.
Iranian Red Crescent rescue workers are working round the clock. They are tired but refuse to give up. Most of the relief workers have lost family members and loved ones. Over 200 people are engaged in the relief operation.
A man picks up a teddy bear from the ground. For a moment he stops, staring at the worn-out toy. The look on his face tells me more than I want to know.
The houses and the lives contained within them are now only piles of rubbles. Clothes, toys and carpets are half buried under the stones and dust. Broken mirrors still hang on the cracked wall.
Cows, some with open wounds, walk randomly through the ruins.
A woman sits, holding a small baby shoe, silently crying, near the entrance of what used to be her home.
People are mourning or walking around trying to find their missing relatives. A man tells me he has lost all his close relatives. He has visited the Red Crescent ID Centre where he identified them all, except one, his uncle. He turns away to continue his search and I notice that the back of his jacket is covered with blood.
No one is expecting to find anyone alive anymore.
So far, 325 bodies have been found, but the figure is expected to increase. There are 450 injured, 30 of them severely.
Most of the dead were firemen killed in the devastating blast which struck at 0937 on the morning of the 18 February. They had responded to the initial derailment and fire which happened five hours earlier.
Among the dead was Ali Akbar Asghari, Rescue and Relief team manager of the Red Crescent branch in Neybashur.
"Mr Asghari saved my life," his driver Habibollah Kooshki said. "We were just about to head back and Mr Asghari told me to park the car at a safe distance from the accident, so I did. Two seconds later, there was a massive explosion."
He continues: "I went back and tried to take care of the victims. When I saw the destruction, I realized that my friend and colleague was among the dead."
Kooshki looks away and adds: "We were almost the same age. Asghari had three children. So do I..."
Among the train's cargo was sulphur, hence the ubiquitous yellow powder. Parts of the wreckage lie all around -- amid the rubble, in nearby fields. Beside the track is a huge crater, 40 metres deep and 150 metres wide.
In the cemeteries people are screaming, crying and grieving- At the same time a new grave is being dug besides them. Innumerable people dressed in black fill the streets of Neyshabur, taking part in funeral proceedings.
As this day of sorrow ends, a proverb by the famous Iranian poet; Omar Kayyam, comes to mind as I head towards the station to take the train back to Tehran:
The Moving Finger writes: and having writ,
Move on: nor all your Piety or Wit
Shall lure it back to cancel half a Line
Nor all your Tears wash out a Word of it.
Things are getting back to normal in terms of infrastructure but for the people in Neyshabour life will never be the same again.