Yemen's Houthi movement and its armed allies seized a military base north of the capital Sanaa on Sunday, dealing a setback to a shaky ceasefire and peace talks in Kuwait aimed at ending a year-long war.
Unlike most of Yemen's soldiers, those at the Umaliqa base had refused to take sides in the civil war between the Iran-allied Houthis and the government, which escalated when a military coalition led by Saudi Arabia intervened in March last year.
The Houthis had tolerated the neutrality until launching a surprise push into the facility in Amran province and seizing its large cache of weapons at dawn, according to local officials.
Several of the soldiers defending the base were killed during the assault, they added.
Abdel-Malek al-Mekhlafi, Yemen's foreign minister and the government's top delegate to U.N.-backed negotiations with the Houthis in Kuwait, said the move had "torpedoed" the talks.
"We will take the appropriate position in response to the Houthi crime at the Umaliqa base in Amran for the sake of our people and country," he wrote on his official Twitter account.
Buttressed by a truce which had been largely holding since April 10, talks in Kuwait had been inching ahead in recent days and the Houthis said Saudi Arabia released 40 Yemeni prisoners it had been holding on Saturday.
For its part, Yemen's Houthi-run state news agency Saba accused the mostly Gulf Arab coalition and Yemeni government forces of violating the truce 4,000 times, saying shelling, bombing raids and warplane overflights had raised tensions.
The war has killed at least 6,200 people and unleashed a humanitarian crisis in the already impoverished country.
Yemen's army has split, and military bases and commanders have mostly either taken the Houthi or government side.