Fighting in war-torn Yemen's Marib province between government forces and Houthi rebels killed around 50 combatants, including a special forces commander, a government source said Saturday.

Earlier this month, the Houthis resumed a push to capture Marib city, 120 kilometres (75 miles) east of the rebel-held capital Sanaa.

The city lies close to some of Yemen's richest oil fields and its capture would be major prize for the rebels.

"Twenty-two members of the government forces and more than 28 rebels have died in the last 24 hours in the fighting that continues unabated on the fronts in Marib province," a government source said.

A Saudi-led coalition launched more than 12 air strikes in support of government forces on the ground, according to rebel channel Al Massirah.

On Friday, more than 60 fighters were killed in fighting in Marib, the bloodiest day since the start of the offensive on February 8.

Since then, clashes have resulted in hundreds of deaths among fighters on both sides, according to government sources, and displaced hundreds of families. The Houthis generally do not disclose their losses.

Yemen has been embroiled in a bloody power struggle since 2014 between its government, supported by the Saudi-led military coalition, and Houthi rebels, who control most of the north.

The grinding conflict has claimed tens of thousands of lives and displaced millions, according to international organisations, sparking what the UN calls the world's worst humanitarian crisis.