LONDON (Reuters) - Most of the jet fuel onboard the U.S.-flagged tanker Stena Immaculate that was hit by a container ship in a collision off Britain's coast remains contained and only two of the vessel's 18 fuel tanks have leaked, owner Stena Bulk said on Wednesday.

The captain of the Solong cargo ship who was arrested after crashing into an oil tanker off the English coast is a Russian national, the vessel’s owner said Wednesday, as maritime experts search for answers.

A cargo ship hit a tanker carrying jet fuel for the U.S. military off eastern England on Monday, setting both vessels ablaze and sending fuel pouring into the North Sea. All 37 crew members aboard the vessels were safe and accounted for,