The raid on hit Mount Noqum area on the eastern outskirts of Sanaa triggered several blasts, an AFP correspondent and witnesses said.

Thick black smoke billowed skywards from the site and other debris was scattered across residential areas at the foot of the hill.

Medical sources on the ground said at least five people were killed and 20 wounded, as witnesses reported ambulances speeding to the site and saying the toll could rise.

An April 21 coalition raid on Sanaa killed 38 people and wounded 532.

Monday's attack came a day ahead of a hoped-for five-day humanitarian truce which launched strikes against Yemen in late March in support of exiled President Abedrabbo Mansour Hadi.