Sean Smith in Iraq

Attacks are often linked: when one unit is hit, another is sent out to help them. The second unit is then ambushed en route

Rounds of ammunition still inside the vehicle were exploding from the heat of the flames

The Bradley vehicle was hit by an IED in Amiriyah, a Sunni neighbourhood in west Baghdad

Amiriyah, Baghdad: Guardian photographer Sean Smith is embedded with the US military in Iraq. The pictures here were taken as the troops he is attached to were called to the site of an explosion - an improvised explosive device (IED) that had destroyed an armoured vehicle.

'The Bradley, upside down, was on fire. Seven died'

".....The Stryker vehicle platoon I was with was acting as the Quick Reaction Force that day, supporting the US military and Iraqi army in the area. When you hear an explosion you don't know what it is. We arrived to find a lot of smoke and moved into a house to assess whether there was shooting still going on.

As we came out, I saw the Bradley, which had been flipped upside down and was on fire. It's a heavy armoured and tracked vehicle, a cross between a tank and an armoured personnel carrier.

You can't patrol that area with Humvees - it's too dangerous. So the troops enter in heavy vehicles and then do foot patrols, visiting houses.

Those troops who could fetched fire extinguishers from their vehicles to try to put the fire out. There was ordnance - we didn't know how much - heating up and going off inside the vehicle.......

People have heard about bombs going off in the mainly crowded Shia areas and markets, but this seems to be a fairly sustained attack on Americans in Baghdad, on a different scale to recent activity in the city."