Yemen's Houthis fired five ballistic missiles towards the Bab al-Mandab area on Monday, according to military media affiliated with the government-allied National Resistance Forces, extending a sharp escalation along Yemen's Red Sea coast.

The National Resistance Forces said two missiles were launched from the vicinity of Al-Hamza military camp in Ibb province and three from the Al-Hawban area east of Taiz. It said all five travelled towards the Bab al-Mandab area.

There were no immediate confirmed reports of casualties or damage from Monday's launches, and the Houthis had not publicly detailed the five launches at the time of publication.

The latest missile fire followed another attack on the government-held port city of Mokha on Sunday involving ballistic missiles and drones, according to Yemeni government-aligned forces.

Mokha, on Yemen's western coast, lies close to Bab al-Mandab, the narrow passage linking the Red Sea to the Gulf of Aden. The strait carries roughly 12% of global trade, according to the Associated Press.

Repeated Houthi attacks have already forced commercial and maritime operations at Mokha port to stop.

Port director Abdulmalik Al-Shara'bi said on Saturday that four security personnel and three port employees had been killed during the recent attacks. He said more than 25 missiles had struck the facility, damaging six wooden vessels, a drilling rig, the quay and other infrastructure. About 1,300 workers have been left without work following the shutdown.

Initial losses at the port were estimated at more than $16 million, according to Al-Shara'bi.

Reuters previously confirmed that an attack on Mokha port on 9 August killed seven people, citing a Yemeni military spokesman, while the transport ministry reported severe damage to the facility. The Houthis said at the time that their strikes in the area targeted Saudi troops and weapons.

The escalation has also extended into the waters around Bab al-Mandab.

On 11 August, three Houthi ballistic missiles struck the Egyptian-owned cargo vessel Tihamah in the strait as it approached Mokha, according to Yemeni authorities cited by AP. Six people were killed and at least nine others were injured.

Reuters reported that four crew members — three Pakistanis and one Indonesian — and two Yemeni rescuers were killed. The Houthis acknowledged attacking a vessel, claiming it was carrying Saudi military equipment. Reuters said the claim about the cargo was not independently established.

The attack was the first confirmed deadly Houthi strike on shipping since the wider Iran war began on 28 February, Reuters reported.

The Houthis announced what they described as a maritime blockade against Saudi Arabia on 20 July, saying it was a response to a Saudi siege of Yemen. Riyadh denies that Yemen is under siege.

Commercial traffic through Bab al-Mandab has fallen substantially. Kpler data cited by Reuters showed an average of 32 ships a day passing through the strait in the week before 12 August, compared with about 50 before the Houthi blockade was announced.

Fighting has intensified on land as well. Yemeni army spokesman Majed Al-Nuzaily said government forces carried out 181 operations against Houthi positions during a 24-hour period over the weekend, using drones, artillery and rocket launchers. He said dozens of Houthi fighters were killed and military equipment and ammunition stores were destroyed. Those battlefield claims have not been independently verified.

The continued attacks around Mokha and Bab al-Mandab have placed one of the world's busiest maritime corridors at the centre of Yemen's renewed fighting, four years after a UN-brokered truce sharply reduced hostilities in the country's civil war.

No independently verified assessment of where Monday's five missiles landed had been released by the time of publication.