DUBAI (Reuters) - Wheat silos in Yemen’s port city of Hodeidah have been damaged by a fire caused by suspected mortar shelling, threatening food supplies for millions of hungry people, the United Nations said.

FILE PHOTO: A ship is docked to unload a cargo of wheat at the port of Hodeida, Yemen April 1, 2018. REUTERS/Abduljabbar Zeyad/ File Photo

The blaze damaged two silos at the Red Sea Mills grains facility, which holds 51,000 tonnes of World Food Programme (WFP) wheat -- enough to feed 3.7 million people for a month in the war-torn country.

“WFP urgently needs to get access ... so we can assess the level of damage and begin transporting the unaffected wheat stocks to areas of Yemen where it is desperately needed,” country director Stephen Anderson said in a statement on Friday.

The WFP has been unable to access Red Sea Mills on the eastern edges of the city since September due to fighting between the Iranian-aligned Houthi movement that controls Hodeidah and other Yemeni forces backed by a Saudi-led coalition that are massed on the outskirts.

A source in the coalition said the silos were hit by Houthi mortars while a Houthi official told Houthi-run media that the fire was caused by coalition artillery fire.

“The world cannot turn a blind eye to these violations, and the coalition will not tolerate them for much longer,” the source from the alliance told Reuters on Saturday.

The Houthis and the Saudi-backed government of Abd-Rabbu Mansour Hadi agreed at U.N.-sponsored talks in December on a ceasefire and troop withdrawal from Hodeidah, the entry point for the bulk of Yemen’s commercial and aid imports.

The truce has largely held but sporadic clashes intensified on Friday as the United Nations struggled to implement the troop withdrawal, a confidence-building step aimed at paving the way for political talks to end the almost four-year war.

Both sides have accused one another of violating the deal.

The port used to supply food to Yemen’s 30 million people became the focus of fighting last year, raising fears that a full-scale assault could cut off supply lines.

“A quarter of a million people are in a catastrophic condition, facing near starvation if assistance doesn’t get to them,” Lise Grande, U.N. Humanitarian Coordinator for Yemen, said in Friday’s statement. “This is the first time we are seeing conditions like this. We need this wheat.”

Yemen descended into war after pro-democracy unrest forced late former president Ali Abdullah Saleh to step down. Hadi was elected to a two-year term to head a transitional government but the Houthis drove him from power in late 2014, prompting the coalition to intervene in 2015 to restore his government.

The Houthis say their revolution is against corruption.