Hello Jan-Olaf,
"British Fleet Destroyers AFRIDI to NIZAM 1937-43", page 89 has the following.

"KHARTOUM and SHOREHAM were hit by shellfire.
KHARTOUM's subsequent loss may have been caused by a shell hitting her after torpedo mounting or a torpedo air vessel may have exploded. Fire broke out and was soon out of control. ADM1/11210 suggests that the explosion of the air vessel of a Mk1X torpedo could be caused by an unexpected flaw probably near the forward end of it and hints that similar air vessel explosions had happened or nearly happened in several British ships of the period.
Because of the intense heat it was impossible to flood the after magazine which exploded, wrecking the stern of the ship. KHARTOUM settled on an even keel with the forward guns and bridge awash. One person was killed and three injured. A dismantling party was left with the wreck that was subsequently abandoned. The majority of the ship's company proceeded to Aden in KANDAHAR".


best regards
Roger