At least four Yemeni soldiers have been killed in clashes with Iran-backed Huthi rebels in the war-torn country's north, an army official said Sunday.

"Four soldiers were killed while confronting Huthi rebels on Saturday evening in the south of Harib district in Marib province," the military official said.

The casualties came as soldiers responded to a "surprise attack", the official added, requesting anonymity as he was not authorised to speak to the press.

Medical sources in Marib confirmed the death toll.

Several other soldiers were wounded in the fighting, which ended hours after the initial Huthi attack on government positions in Harib, medics and the army official said.

Information about Huthi casualties was not immediately available.

Flare-ups between Huthi rebels and the Saudi-backed Yemeni forces are relatively common in Marib -- the government's last northern stronghold.

A Saudi-led military coalition intervened in 2015 to back the government after the Huthis seized control of the capital Sanaa and large swathes of the country.

The war has killed hundreds of thousands of people both directly and indirectly, and triggered what the United Nations calls the world's worst humanitarian crisis, with millions of people displaced.

A United Nations-brokered ceasefire that took effect in April last year brought a sharp reduction in hostilities.

The truce expired in October, though fighting largely remains on hold.