The Iran-backed Houthis, who claim to back Palestinians besieged by Israel in the Gaza Strip, have attacked merchant ships with drones and missiles, forcing shipping companies to divert and take a longer route around Africa's southern tip.

The tanker Egeorgis, chartered by British major BP to carry vacuum gas oil from Jamnagar, India to Texas, was en route to the Cape of Good Hope off Africa's east coast on Friday, according to ship tracking data from ship tracking data firm LSEG.

BP normally transports vacuum gas oil cargoes through the Red Sea. The new route adds nine days to the journey between India and the US Gulf Coast. Vacuum gas oil is a refined raw material used to make gasoline and diesel.

A BP spokesman declined to comment. But he referred to an earlier report on the company's decision to replace the ships. The company said on Tuesday it would avoid the Red Sea and operate ships around the Cape of Good Hope.

LSEG data also showed that the Sonangol Cabinda, a tanker chartered by Equinor and carrying crude oil from Texas to India, made a 180-degree turn in the open Red Sea on Thursday and headed through the Suez Canal towards the Mediterranean.

The maritime alliance announced last week includes 20 countries, the US said. However, some have not confirmed their participation, while others have said that measures to protect navigation in the Red Sea will be part of existing maritime agreements. The lack of practical details for shipping companies still creates confusion for those avoiding the area.

“We have temporarily suspended new operations involving traffic through the region,” an Equinor spokesperson said on Tuesday. Vessels in the area are currently being diverted or temporarily stopped, the spokesman said.

The Houthi attacks have prompted shipping companies to change their routes, leaving many African ports congested with the number of ships entering their waters.

“War risk premiums for tankers sailing through the Red Sea have risen recently, making it less expensive for those chartering the longer route (Cape of Good Hope),” said Jay Morrow, an analyst at energy data firm Vortexa.

According to LSEG data, many tankers leaving ports east of Suez bound for non-US destinations diverted or altered their course to avoid the Red Sea.

Other diverted tankers include Pao Olympus, chartered by Equinor. The tanker left the US Gulf Coast on December 10, changed course while crossing the Atlantic Ocean to Suez, turned 90 degrees and set its destination for Durban, South Africa.

Meanwhile, the Almi Globe, a tanker chartered by BP, was diverted in the Mediterranean. The ship was on its way to Suez until Thursday.