The United Nations Security Council authorized African and French troops Thursday to use force to halt deadly chaos in the Central African Republic.
The 15-member council unanimously backed a French-drafted resolution that gives a UN mandate to about 4,800 African and French troops being sent to the impoverished nation as Muslim-Christian strife grows.
It orders UN leader Ban Ki-moon to report in 90 days on whether a full UN peacekeeping mission should be sent. Ban has said up to 9,000 troops could be needed for the crisis.
The vote was held as scores of people were were killed in Bangui in scenes that highlighted warnings by the UN, France and the United States that a Rwanda-style genocide could erupt.
France said the council has a duty to act to end anarchy that has grown since rebels ousted the Central African Republic's president in March.
Resolution 2127 gives a 12-month mandate to the African-led International Support Mission in Central African Republic (MISCA) to stabilize the country and "protect civilians."
French forces can use "all necessary measures" to support the African contingent.
There are currently about 2,500 troops in MISCA, which will eventually reach 3,600. France has 600 troops there and plans to increase this to 1,200.
The African troops will launch into their mission in an "aggressive fashion," African Union representative to the UN Tete Antonio told the Security Council.
France ordered 250 troops onto the streets of Bangui after the latest reports of mass killings.
France's UN envoy Gerard Araud warned that there was a risk of "mass atrocities" but said the French and African forces would have an "immediate" impact.
He said they would concentrate on reestablishing order in Bangui and then seek to secure the main roads to other cities.
Highlighting the growing Christian-Muslim tensions, Araud said: "History has taught us what can happen. History must make us avoid the worst. History obliges the Security Council to act."
The resolution orders an arms embargo against Central African Republic and the setting up of a UN commission of inquiry into mass killings, rapes and looting since March, when rebels forced President Francois Bozize to flee.
It highlighted the "total breakdown in law and order" in the state.
UN leader Ban said the deployment of the French and African troops was "vitally needed" and "sends a message of international resolve to respond to the crisis," according to his spokesman Martin Nesirky.
Ban said it was urgent for the African force to move in "with all speed so that the people of the Central Africa Republic can be spared further suffering, insecurity and violence."
The United States also gave strong backing to the resolution.
US Ambassador Samantha Power said there had to be a "credible" international force in Central African Republic and the troops had to move out "aggressively" to end the "carnage."
The United States has pledged $40 million to MISCA and given strong political backing to the mission. But it has not said whether it would support a full UN peacekeeping force.
"Our response will be based on what is most appropriate for saving lives," Power said.
Human Rights Watch said the resolution was a "a crucial step" toward halting the strife.
But HRW's UN specialist Philippe Bolopion said the African force would be only "a temporary fix."
"Bolder steps are urgently needed. As soon as the UN is ready to proceed, the Security Council should authorize the deployment of a force of blue helmets with sufficient numbers and equipment to protect the civilians most at risk," Bolopion added.