Yemeni officials and witnesses say fighting between Saudi-led coalition forces and Shiite rebels has flared up again around the Red Sea port city of Hodeida despite United Nations calls for a ceasefire there.
They say coalition airstrikes hit the rebels, known as Houthis, in and around Hodeida late on Monday.
Earlier, the rebels said they had fired a ballistic missile the previous night into Saudi Arabia in response to an attempted border incursion and another airstrike.
The officials spoke on condition of anonymity as they weren't authorised to talk to reporters; the witnesses did so for fear for their safety.
The coalition has waged war against the rebels since March 2015; tens of thousands of people have been killed.
The UN is trying to end the conflict and has proposed a new resolution.
