ADEN, Thirteen people were killed in a fire on Saturday that broke out near an oil pipeline damaged by sabotage in the west of war-torn Yemen, a government official said.

"Dozens of people had gathered at the site of the pipeline with bowls and other containers to fill with petrol spilling from the pipeline" in Hodeida on the Red Sea, the official in Yemen's recognised government said.

He said the fire broke out because of the use of an electricity generator, giving a revised casualty toll of 13 dead, 26 injured and eight missing.

Yemeni government forces are preparing for an assault on the nearby port of Hodeidah held by Houthi rebels.

Fighters aligned to President Abd Rabbo Mansour Hadi and the government's Arab allies are building up around Hodeidah, despite UN calls for a de-escalation in tensions around the town.

Meanwhile, the government of Yemen announced that work is underway to reopen Al-Mokha port on the country's Red Sea coast, the Saudi Press Agency reported on Saturday.

Yemen's Deputy Minister of Transport Nasser Sharif told his country's news agency, "The ministry is working to take the necessary measures to conduct work in the ports of Al-Hodeidah and Al-Mokha" after their liberation from Houthis and that it is assessing procedures to "transfer the presidency of the Red Sea Ports to Al-Mokha after the government's approval."

Sharif said the port of Al-Hodeidah has been stopped, noting that it has become an outlet for smuggling of weapons and money, which the militia are benefiting from by controlling the port's trade activities.

The restoration of the port of Al-Hodeidah by the Yemeni government and their coalition partners will be a major blow to the Houthis who use the port as a channel to transport weapons and as well as disrupt maritime navigation.

More than 7,700 people -- most of them civilians -- have been killed in fighting between Shiite Huthi rebels and the Yemeni government backed by a Saudi-led Arab coalition since March 2015, according to the United Nations.