Having received very serious injuries the soldier received medical treatment at Basra Air Station before being flown back to the UK.
"Sadly, and despite the best possible medical care, the soldier died as a result of the injures this afternoon," the MoD said in a short statement.
"The soldier's next of kin have been informed and have requested a period of grace before further details are released."
The soldier, from the Royal Logistic Corps, was on a routine re-supply convoy to Basra Palace, the main British base in Iraq's second city, when the attack took place.
Today's death is the 148th since UK forces began operating in Iraq in 2003, continuing a recent upsurge in the rate of fatalities.
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