Nine people were also wounded in the attack on several areas of the city and its outskirts, they said, adding the nine dead included three children and their parents.

A spokesman for the Saudi-led alliance of Arab countries could not immediately be contacted.

The coalition, which began operations in Yemen in March last year to try to reverse the rise to power of the Iran-allied Houthi group, has repeatedly said it does not target civilians.

UN-sponsored talks to try to end the fighting that has killed more than 10,000 people collapsed in failure last month and the Houthi movement and allied forces loyal to former president Ali Abdullah Saleh resumed shelling into neighbouring Saudi Arabia.