Danish shipping company Maersk said on Friday it was suspending its vessels’ passage through the key Bab al-Mandeb Strait, and the German container shipping line Hapag-Lloyd said it would pause journeys in the Red Sea until Monday.

The announcements come after attacks from Houthi-controlled Yemen hit two Liberian-flagged ships in the Bab al-Mandab Strait earlier on Friday, a US defence official told the news agency Reuters.

A projectile, believed to be a drone, struck one of the vessels, causing a fire but no injuries, the official said.

The ship was identified as the Liberia-flagged Al-Jasrah, a 370-metre (1,200-foot) container ship built in 2016.

Private intelligence firm Ambrey said the vessel, owned by German transport company Hapag-Lloyd, “sustained physical damage from an aerial attack” north of the Yemeni coastal city of al-Makha (Mocha).

“The projectile reportedly hit the port side of the vessel and one container fell overboard due to the impact. The projectile caused a fire on deck” that was reported over radio, Ambrey said.

Two ballistic missiles were fired in the second attack, one of which struck a vessel, causing a fire, which the crew was working to extinguish, the US official said.

The Associated Press news agency identified the vessel struck in the second attack as the Liberain-flagged MSC Palatium III.

“Following the near-miss incident involving Maersk Gibraltar yesterday [Thursday] and yet another attack on a container vessel today, we have instructed all Maersk vessels in the area bound to pass through the Bab el-Mandeb Strait to pause their journey until further notice,” said a statement from Maersk, one of the world’s largest shipping companies.

German container shipping line Hapag-Lloyd has paused all its sailings through the Red Sea until December 18, a spokesperson said on Friday.

“Then we will decide for the period thereafter,” the spokesperson added.

Houthis claim responsibility

The Houthis said in a statement that they had fired missiles at two ships – the MSC Alanya and MSC Palatium III. The statement did not mention Al Jasrah.

An MSC spokesperson said there had been no attack on the Alanya. Asked about the Houthi claim of an attack on the Palatium III, the spokesperson provided no further comment.

The Houthis said both vessels had been heading to Israel.

However, Alanya and Palatium III both listed Jeddah in Saudi Arabia as their destination, according to data from ship tracking and maritime analytics provider MarineTraffic.

“We will continue to prevent all ships heading to Israeli ports until the food and medicine our people need in the Gaza Strip is brought in,” the Houthi statement said.

“We assure all ships heading to all ports of the world apart from Israeli ports that they will suffer no harm and they must keep their identification device on,” it said.

The Iran-aligned Houthis, who control much of Yemen but are not recognised internationally, have said that they are targeting shipping to pressure Israel during its offensive on Gaza, which has killed more than 18,700 people in the two-month-old war against Hamas, which governs the enclave.

Speaking in Tel Aviv, US National Security Adviser Jake Sullivan said, “While the Houthis are pulling the trigger, so to speak, they’re being handed the gun by Iran.”

The Houthis have said they will target any ship travelling to Israel, irrespective of its nationality, and are now launching regular attacks, although they are mostly unsuccessful.

A Hapag-Lloyd spokesman told the AFP news agency that its ship was en route from the Greek port of Piraeus to Singapore. There were no casualties and the vessel was now travelling on towards its destination.

‘Threat to commercial shipping’

Sullivan, who is visiting Israel, said the Houthi rebels were threatening freedom of movement in the Red Sea, vital for massive oil and goods shipments.

“The United States is working with the international community, with partners from the region and from all over the world to deal with this threat,” he told reporters.

The attacks on Friday occurred near Bab al-Mandab, the narrow strait between Yemen and northeast Africa through which much of global commerce flows.

Some 40 percent of international trade passes through the area, which leads to the Red Sea, Israel’s southern port facilities, and the Suez Canal.

Insurance costs for ships transiting the area have jumped in recent days, amounting to increases in the tens of thousands of dollars for larger ships like oil tankers, reports say.

While warships passing through the Red Sea are well equipped and can retaliate, commercial vessels do not have the same protections.

Crews under fire by heavy weapons typically abandon the bridge and control their vessels remotely from an armoured citadel.

Israel’s regional rivals have cited the high Palestinian death toll and occupation of much of Gaza as motivating their attacks, raising the risk of the conflict spreading further.

The rebels have tried to hijack and capture several ships, succeeding at least once in November. They typically order them to surrender and head to a Yemeni port, and open fire if they do not comply.

US, French and British warships are patrolling the area and have shot several missiles out of the sky.