The United Nations Security Council called on Shiite rebels to leave the northern Yemeni city of Amran, which they seized in a major advance toward the capital.
In a unanimous declaration, the council's 15 members threatened targeted sanctions on those impeding the political transition process in Yemen and renewed their support of President Abdrabuh Mansur Hadi.
They expressed "grave concern about the serious deterioration of the security situation" and "deep regret" at the more than 150 people killed.
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The council members also demanded that "the Huthis, all armed groups and parties involved in the violence withdraw and relinquish control of Amran and hand over weapons and ammunition pillaged in Amran to the national authorities loyal to the government," a statement said.
Calling for all sides to disarm and "swiftly" implement existing ceasefire agreements, the members also asked military units to "remain committed to their obligation of neutrality at the service of the state."
Amran, 30 miles (50 kilometres) north of Sanaa, has since February been the scene of fighting between troops and Huthi rebels, as well as tribes on both sides, as the rebels advanced from their mountain strongholds toward the capital.
Home to an estimated 120,000 people, the city fell into rebel hands on Tuesday after a three-day battle that has uprooted some 10,000 families, according to the Red Crescent.
By seizing Amran, the rebels have made a major advance towards the capital Sanaa, posing a threat to Hadi's government.