A 32-year-old British soldier has died in a firearms incident in Iraq.
More than 50 British troops have been killed in Iraq
Sergeant John Nightingale, from Leeds, died in a "tragic incident", the Ministry of Defence said on Thursday.
It happened on 23 September at Shaibah, near the southern city of Basra.
Sgt Nightingale's death did not involve enemy fire, the MoD said, and the Royal Military Police are investigating exactly what happened.
He was a Territorial Army soldier with 217 Transport Squadron, part of 150 Regiment (Volunteers) of the Royal Logistic Corps, based at Churchill Barracks in Leeds, the MoD said.
He was serving in Iraq with 27 Regiment RLC, at Shaibah Logistic Base and helped manage the distribution of supplies throughout Iraq.
Sgt Nightingale's death was described as a "terrible shock" by Lieutenant Colonel John Bevan, commanding officer of 27 Composite Logistic Support Regiment.
"Sergeant John Nightingale was a good man, a strong character and excellent senior Non-Commissioned Officer who had an impact on the working and social lives of many in the unit during our tour here in Iraq.
"He will be missed by all of us.
"He was a popular character, well regarded by those who met and worked with him and his loss will be felt throughout the regiment," he added.
Fifty-one British soldiers have died in Iraq since the war began in March.
Twenty died in action and 24 in accidents, including "friendly fire." The rest are either under investigation or were from natural causes.
Sgt Nightingale's death comes a month after Fusilier Russell Beeston, from Glasgow, died in a confrontation with a group of Iraqis in Ali al-Sharqi.