Houthi rockets kill seven children in Yemen's Marib

The young victims were playing in a courtyard when the missile hit, said Abdel Ghani Shaalan, Marib's deputy regional director of security.

Twenty-five other civilians including women and children were also wounded when two other rockets hit a house and a shop front, Shaalan added.

The Katyusha rockets were fired by the rebels from Mount Haylan, 15 kilometres (10 miles) west of Marib.

Saleh al-Shaddadi, the director of Marib's main hospital, where casualties were admitted confirmed the death toll on Tuesday.

Frequent clashes break out in Marib and surrounding government-held provinces as forces loyal to Abdrabbuh Mansour Hadi attempt to push towards rebel-controlled areas to the north and west of the oil-rich region.

The plight of Yemen's children made international headlines in recent weeks when a dispute broke out between Saudi Arabia and the UN who published a report accusing the kingdom of killing hundreds of children during the war on Houthi rebels.

The revelations prompted the UN to put the Saudi-led coalition fighting the war on a blacklist of child rights violators but the move was later reversed after the kingdom threatened to withdraw funding to UN agencies.

Saudi Ambassador Abdullah al-Mouallimi said the number of child deaths blamed on the coalition was "wildly exaggerated", and later proclaimed that the decision to be taken off the list was "irreversible".

The coalition launched an air campaign in support of Yemen's President Hadi in March 2015 to push back Houthi rebels after they seized the capital Sanaa and many parts of the country.

The war has left some 6,400 people dead, with more than 80 percent of the population in desperate need of humanitarian aid, according to the UN.