Aug 14 (Reuters) - Yemen's internationally recognised

government said the Houthis fired six ballistic missiles at the

Red Sea port of Mocha on Friday, killing four civilians, amid an

escalation in hostilities between the Iran-aligned group and its

Saudi-backed opponents.

The escalation comes at a time of heightened regional tensions

over the U.S.-Israeli war on Iran, where the Houthis have

emerged as a key front, raising the prospect of a return to

large-scale conflict in Yemen.

The armed forces aligned with the Yemeni government said the

attack targeted civilian infrastructure and national assets at

the port. Initial reports said four civilians were killed and

several fishing boats were set on fire.

The Houthis said they had attacked what they described as

Saudi-backed military build-ups, weapons and warships belonging

to Saudi-backed forces and "mercenaries" in Mocha with a large

number of ballistic missiles, destroying boats and weapons.

Separately, the Houthi-run SABA news agency cited a military

source as saying the group had targeted an Aramco facility in

the Saudi city of Najran with a drone.

The source said the attack was a response to what it

described as Saudi military aircraft entering airspace over the

northeastern part of Yemen's Saada governorate. The report did

not identify the precise target or say whether it had been hit.

There was no immediate confirmation from Saudi authorities

or Aramco.

The reported attacks follow a rise in hostilities between

the Houthis and Yemen's internationally recognised government.

On Thursday, the Houthis said they had attacked an Aramco

refinery in Saudi Arabia's Jazan with two drones.

On July 20, the Houthis announced a naval blockade on Saudi

Arabia in the Red Sea, saying it was a response to what they

called a Saudi siege of Yemen, an allegation Riyadh denies. A

Saudi-led coalition responded with air strikes on what it said

were Houthi military facilities in the port city of Hodeidah

linked to threats against commercial shipping.

Yemen has been engulfed by conflict since the Houthis seized

the capital Sanaa in 2014, prompting a Saudi-led military

intervention the following year. Major fighting largely subsided

under a U.N.-brokered truce in 2022, but efforts to secure a

lasting political settlement have stalled.