Aden- The U.N. Security Council today imposed an arms embargo targeting the Iran-allied Houthi rebels who now control most of Yemen as battles in the south of the country intensified.

It also demanded the Houthis stop fighting and withdraw from areas they have seized, including the capital Sanaa.

On the ground, southern militiamen claimed gains against the Houthis on several battlefronts across southern Yemen, including districts of the port city of Aden, the last stronghold of loyalists to Saudi-backed President Abd-Rabbu Mansour Hadi.

Iran meanwhile prepared to submit a four-point peace plan for Yemen to the United Nations on Wednesday, state media said.

Tehran's proposal includes a call for an end to Saudi-led air strikes against the Houthis and is likely to anger Riyadh, which accuses Iran of meddling in the affairs of its southern neighbor.

In New York, the U.N. Security Council imposed a global asset freeze and travel ban on Ahmed Saleh, the former head of Yemen's Republican Guard, and on Abdulmalik al-Houthi, a Houthi leader.

Saleh's father, former Yemen President Ali Abdullah Saleh, and two other senior Houthi leaders, Abd al-Khaliq al-Huthi and Abdullah Yahya al Hakim, had been blacklisted by the Security Council in November.

The Security Council also expressed concern at what it called "destabilizing actions" taken by former President Saleh, including supporting the Houthis.