Renewed clashes between forces loyal to Yemen’s internationally recognized government and their rivals, the Iran-backed Houthi rebels, left five fighters dead in the strategic port city of Hodeida, an official said.

The senior security official, who spoke on condition of anonymity to talk to reporters, said the casualties were from both sides of the conflict.

During the fighting, shells also fell on a port wheat warehouse in Hodeida, which handles about 70% of Yemen’s commercial and humanitarian imports, according to the same official.

In 2014, the Houthis overran most of the country’s north including the capital, Sanaa, forcing the government of President Abed Rabbo Mansour Hadi to flee to the country's south In 2015, Saudi Arabia intervened against the Houthis by mobilizing a military coalition in an effort to bring Hadi's government back to power.

However, the five-year war has so far mostly stalemated on the battlefields, while also causing the world’s worst humanitarian crisis.

The rebel-run Al-Masirah satellite TV channel said that more than 70 shells hit different parts of Hodeida, including the city’s international airport.

Despite a U.N. brokered truce around Hodeida, clashes have sporadically erupted between Hadi’s forces and the Houthis, disrupting the lifeline of humanitarian assistance to millions of civilians in need.