LONDON, Reuters Shipping companies remain in the dark over a new international navy coalition being assembled by the United States to combat attacks in the Red Sea, with many vessels continuing to avoid the area or cancelling contracts, sources said on Wednesday.

The sources, who include shipping and maritime security officials, say few practical details are known about the initiative launched on Tuesday by Washington or whether it will directly engage in the event of further armed attacks at sea.

Iranbacked Houthi militants in Yemen have since Nov. 19 stepped up attacks on vessels in the Red Sea to show support for Hamas as Israel39;s military offensive in Gaza continues.

Their leader said on Wednesday the group would strike U.S. warships if it is targeted by Washington.

Houthi fighters have fired missiles and launched seaborne assaults on ships from fast boats. Missiles fired have been repelled by U.S. warships.

There are still a number of unknowns with the coalition. We don39;t know exactly how many warships will be involved, how long it will take those vessels to get to the region, or their rules of engagement and the actual protection scheme that will be put in place, said Corey Ranslem, chief executive of British maritime risk advisory and security company Dryad Global.

Globally this is a fairly small area, however providing protection to commercial vessels in this region could be a major undertaking depending on the number of vessels along with any changes…