Baghdad (North Gate) War Cemetery, Iraq

The following man of the 9th King's is buried in this cemetery:

Private Alfred Jones Died 25/09/1917

This is a mystery! Pte Jones' service number suggests that he was originally 9th Bn but the Commonwealth War Graves Commission records state that he died with the 7th Bn. King's Liverpool Regt. But that doesn't explain why he is buried in Baghdad, since both the 7th & the 9th were serving on the Western Front when Pte Jones died. If anyone can solve this mystery I would be happy to hear from them.