ADEN, Yemen -- A Houthi official said Saturday that US and British forces flew spy drones "for hours" over the Yemeni port city of Hodeidah, where conflicting reports of a new airstrike emerged.

Ali Ahmed Kashar, the Houthi deputy governor of Hodeidah, told Xinhua by phone that his group saw more spy drones over the city from early morning to evening. He also denied reports from local and international media over new airstrikes on Houthi sites in Hodeidah.

Earlier, local media said a navy base near the port was hit by US-led coalition planes. Residents told Xinhua they heard loud explosions and ambulance sirens. They also said the Houthis deployed heavily in Hodeidah neighborhoods after the blast.

The Houthi official made no comments on the explosions.

The Houthis have reportedly used the Ras Kutheb base to attack commercial and military ships in the vital maritime region.

Hodeidah, on the Red Sea coast, is a strategic city with one of Yemen's largest ports. The Houthis have controlled Hodeidah since 2014, and the port is a lifeline for humanitarian aid and commercial supplies entering Yemen.

Earlier Saturday, UN Special Envoy for Yemen Hans Grundberg urged all parties to show restraint amid a dangerous escalation in regional tensions.

On Friday, the US and Britain launched strikes on Houthi targets in the Yemeni capital of Sanaa and other areas. The strikes were in response to the Houthis' attacks in the Red Sea on what they called "Israeli-linked ships" to pressure Israel to stop its assaults in the Gaza Strip.

The civil war in Yemen has raged since 2015, causing one of the world's worst humanitarian crises, with millions facing famine.