Chemical tanker Stolt Magnesium hit by explosion off Omani coast, manager says

LONDON, July 14 (Reuters) - The chemical tanker Stolt Magnesium caught fire on Tuesday following the "explosion of an unidentified external device" as it was sailing in the Arabian Sea off the coast of Oman, according to its manager Stolt Tankers, the main unit of Norwegian shipping company Stolt-Nielsen's. • The incident occurred at 12:40 a.m. (2040 GMT on Monday) and caused a fire in the vessel's engine room, it said in a statement. • All of the vessel's seafarers were safe and accounted…