SANAA, Yemen (AP) — Tanks and armored vehicles deployed in Yemen's capital Tuesday in the face of protests by tens of thousands of supporters of Shiite rebels who are demanding the government step down.

Protesters were responding to a call by Abdel-Malek al-Hawthi, the top leader of the heavily armed Hawthi group that overran northern cities. He has given the government until Friday to meet their demands of reinstating fuel subsidies and relinquishing power.

Military officials said that Yemen's elite "Presidential Forces" were on standby in case of any attack, taking positions near government buildings, foreign missions and main intersections. They spoke on condition of anonymity because they were not authorized to speak to journalists.

Yemen's Supreme Security Committee, its most senior security body, warned Tuesday it will take "all measures to ensure the safety and security of the country."

The committee listed what it said were "worrying signs" of militiamen deploying on rooftops in some areas of the capital, Sanaa, as well as armed Hawthi convoys entering the capital and setting up checkpoints,

Yemeni President Abed Rabbo Mansour Hadi said in televised remarks during a government emergency meeting that he would take "decisive and legal action" against anyone disrupting the country's security, describing the demonstrations as "unacceptable."

Ten of Yemen's Western and international allies said in a joint statement that the Hawthi moves were "antagonistic, militaristic and disrespectful."

"Threats of the kind you have made against the government are not a way to demonstrate any validity of your claims," said the statement posted on the website of the U.S. Embassy in Sanaa. It called upon Hawthis to withdraw from the capital and hand over their weapons.

"Any action aimed to incite or provoke unrest and violence is unacceptable, and will be strongly condemned by the international community," said the statement, signed by "The Group of Ten Ambassadors," in reference to the countries which backed the power-transfer deal that saw former President Ali Abdullah Saleh relinquish power after a yearlong uprising in 2011.

Hawthi spokesman Mohammed Abdel-Salam criticized the envoys' message, saying the group rejects the "foreign mandate" and vowed to continue "our blessed revolution peacefully."

The Hawthis waged a six-year insurgency in the north against Saleh, which officially ended in 2010. After Saleh's ouster, they have fought ultraconservative Islamists in several northern cities and towns, accusing them of turning their strongholds into incubators of extremism.