The Yemeni oil ministry affiliated with the Houthis says countries of the Saudi-led coalition and their mercenaries looted more than 18 million barrels of the country’s oil exports last year.

Speaking at a press conference in the Yemeni capital Sana’a on Saturday, Ahmed Daris said the coalition “looted more than 18 million barrels of oil exports last year and sent their money to the Saudi National Bank," Yemen's Arabic-language al-Masirah news website reported.

Daris also called on the United Nations to shoulder its responsibility in facilitating the release of oil shipments detained by the Saudi-led coalition waging war on the impoverished nation.

He warned the Saudi-led coalition that the continued detention of the oil tankers will further motivate Yemeni people to join anti-Saudi frontlines.

“Free oil tankers, our people will not surrender to the continued detention, but this will be an incentive to move to frontlines,” he said.

Saudi Arabia and its allies launched military campaign on Yemen in March 2015 with the aim of reinstalling the government of former president Abd Rabbuh Mansur Hadi and crushing the Houthi Ansarullah movement.

Yemen’s southern areas are controlled by Saudi-backed officials of the former Yemeni government. Saudi Arabia has taken control over the provinces' seaports and airports, using them to deploy hundreds of troops in the region.

A series of documents obtained by some media outlets in August last year pointed to Saudi Arabia's intention to build an oil port in Yemen's al-Mahra governorate in the country's southeast, where Saudi and Emirati troops are present.

The documents pointed to Saudi Arabia's intention to develop the port, which would extract and export petroleum.

In a letter addressed to the kingdom's ambassador to Yemen, a Saudi-based marine construction company, Huta Marine, thanked the official for trusting the company's capabilities by asking it to present a technical and financial proposal for the port's design.

Experts say the pipeline would allow the kingdom not to be constrained to the Strait of Hormuz or the Bab el-Mandeb Strait, both strategic choke points that affect its current oil shipping routes.

According to a report by the Armed Conflict Location and Event Data Project (ACLED), a nonprofit conflict-research organization, the Saudi-led war has so far claimed the lives of about 56,000 Yemenis.

The kingdom has also imposed an all-out blockade on Yemen, which according to the UN is now the scene of the world’s worst man-made crisis.