Navies of nine countries are joining the United States naval force defending commercial ships passing the Red Sea as more shipping lines avoid the trade route in the face of drone and missile attacks from Houthi rebels in Yemen.

The multinational Combined Maritime Force is expected to ramp up its security operations in the Red Sea, the Bab el-Mandeb Strait near Yemen and the Gulf of Aden with the additional support from the United Kingdom, Bahrain, Canada, France, Italy, Netherlands, Norway, Seychelles and Spain.

US Defense Secretary Lloyd Austin said in a statement said the new coalition partners will help ensure freedom of navigation in the sea lane where 12 percent of global trade passes but is being disrupted by the Iran-backed Houthis.

The Yemen rebels on Monday attacked the Norwegian-owned Swan Atlantic and the MSC Clara in an attempt to pressure Israel over its war against Hamas militants.

In a statement, the Yemeni rebels vowed to "continue to prevent all ships heading to Israeli ports… from navigating in the Arab and Red Seas" until more food and medicine is allowed into Gaza.

The Houthis back the Hamas terrorist group fighting Israeli forces in Gaza Strip

The Swan Atlantic's owner, Norway's Inventor Chemical Tankers, said in a statement the ship was carrying biofuel feedstock from France to Reunion Island.

It said the vessel has "no Israeli link" and was managed by a Singaporean firm, adding that the Indian crew were unharmed and the vessel sustained limited damage.

British oil giant BP and Taiwan shipping firm Evergreen announced Monday the suspension of their transit through the Red Sea.

Frontline, one of the world's largest tanker companies, also said it was rerouting ships and would "only allow new business" that could be routed via South Africa's Cape of Good Hope.

That route is far longer and uses more fuel.

The Red Sea attacks have forced insurance companies to significantly increase premiums on ships, making it uneconomical for some to transit through the Suez Canal.

Italian-Swiss giant Mediterranean Shipping Company, France's CMA CGM, Germany's Hapag-Lloyd, Belgium's Euronav and Denmark's AP Moller-Maersk — the latter accounting for 15 percent of global container freight — have all stopped using the Red Sea until further notice.

The attacks have become "a maritime security crisis" with "commercial and economic implications in the region and beyond," Torbjorn Soltvedt of analysis firm Verisk Maplecroft told Agence France-Presse.