The Yemeni military said it wrested control of several northern towns from the Iran-backed Houthi rebels on Monday as government forces try to push back recent gains by the militants.
Yemeni forces, supported by Saudi air power, announced on Twitter that they retook cities in the vast Khub Walshaaf district on the border with Saudi Arabia.
The battles over the past two days killed at least 35 fighters from both sides and wounded dozens of others.
The Houthis had overrun the area in recent days after they captured Hazm, the capital of oil-rich Al Jawf province.
Hazm is a strategic prize for the Houthis, paving the way for a march towards the central province of Marib, a shrinking anti-Houthi stronghold in the country’s north.
Gains by the Houthis so close to Saudi Arabia’s southern border raised alarm in the kingdom.
To help the army fend off the Houthi advance, the Arab Coalition staged at least 18 air strikes on Khub Walshaaf, the Houthis said on Monday.
If Houthi fighters reach the Saudi border, it would be a breakthrough in their quest to solidify control of the country’s north and would open a new front against Saudi forces.
The Yemeni army has been trying to retake Hazm over the past week.
After the Houthi advances, UN envoy to Yemen Martin Griffiths called for a halt to fighting before Yemen slips “back into large-scale conflict and another humanitarian tragedy".
“The military adventurism and quest for territorial gains that we have seen since mid-January in northern Yemen are leading us away from peace,” Mr Griffiths said on a weekend visit to Marib.
The city, a sort of haven for hundreds of thousands of Yemenis who have fled Houthi offensives since the start of the war, has become home to thousands more Yemeni families displaced by the latest round of fighting.
The International Organisation of Migration estimated that 39,360 people were forced from their homes between January 1 and March 7.
Most of these were from Al Jawf province, Hazm and around Marib.
The fighting in January came after a lull that Mr Griffiths at the time described as one of the most peaceful periods since the war began.
He said it had raised hopes that his diplomatic efforts would lead to a broader breakthrough.
But government officials have described the resurgence of violence as partly the result of a political agreement made in December 2018 to avert a coalition-backed offensive to retake the port city of Hodeidah.
The deal stipulated that all sides would pull troops back from the city and that prisoner swaps would take place.
The agreement has not been fully carried out, with the Houthis refusing to comply with several parts, including withdrawal from the city.
But military officials say the Iran-backed group has redeployed its troops from the city to Al Jawf, leading to the string of rapid gains in recent weeks.