Speaking on condition of anonymity, a provincial government official berated the Houthis for trying to prevent the ship from docking at the Aden port, which is currently controlled by pro-government forces.
"The Houthis fired shells at a ship chartered by the UN that was carrying 7,000 [metric] tons of food… when it was within a nautical mile of Aden's port," the official said.
He added that the vessel was not hit, but that it was forced to turn back from Aden as a result of the shelling; initially, the ship set off from Djibouti, a nearby African country which is being used by the UN as a hub for Yemen-bound humanitarian aid.
The Houthi faction, the main political opposition force in Yemen, seized control of the capital Sanaa and several other cities in late 2014, forcing President Abd Rabbuh Mansur Hadi to flee the country.
According to the World Health Organization, almost 2,000 people have already been killed and 8,000 more wounded in the Yemen conflict.