The African Union has imposed sanctions against the leader of Mali's military coup and allies the bloc says are helping prevent the return of constitutional order.

Commissioner Ramtane Lamamra said the AU has imposed a travel ban and asset freeze against junta leader Captain Amadou Sanogo and his associates effective immediately.

He said the AU made the decision after a meeting at its headquarters Addis Ababa on Tuesday.

The United Nations Security Council was also holding an emergency meeting on the Mali crisis at its New York headquarters Tuesday.

The junta began experiencing harsh new economic sanctions on Tuesday imposed by the Economic Community of West African States, or ECOWAS.

The group decided Monday to immediately close all borders between Mali and member states, and cut off the currency flow to the country, which relies on the region's central bank.

Long lines quickly formed at gas stations in the capital, Bamako, where many residents turned up with jerrycans and plastic jugs. Many said they are stockpiling fuel because they are worried the country will soon run out.

Soldiers seized power from President Amadou Toumani Toure on March 22, accusing him of failing to provide the army with enough resources to stop Tuareg rebels in the north.

Former Nigerian president Olusegun Obasanjo told VOA he is confident ECOWAS can resolve the crisis. He says the group should encourage soldiers to return to their barracks, followed by a transition to elections and a return to democracy.

“We have to acknowledge what you may call legitimate complaints of the military, that they were given [a] task without adequate tools to perform the task. I think our leaders having acknowledged that legitimate situation that you found yourself, but the way you've gone about it is not the right way, and that way is not acceptable.”

Tuareg rebels launched an offensive on Friday and rapidly seized three key cities that were still under army control.

An Islamist militant group called Ansar Dine has also entered some areas and started imposing sharia, or Islamic law. Ansar Dine has been linked to the al-Qaida branch in northern Africa known as al-Qaida of the Islamic Maghreb, or AQIM.

On Tuesday, the United Nations said at least 200,000 people have fled the unrest in northern Mali, roughly half of them seeking refuge in neighboring Burkina Faso and Mauritania.

The heavily armed rebels arrived in northern Mali after the fall of neighboring Libya and launched an insurgency in mid-January. Tuareg separatists have been seeking autonomy for decades.

The ECOWAS heads of state met in Senegal's capital, Dakar, after the end of a 72-hour deadline for Mali's military junta chiefs to restore constitutional order.

Coup leader Sanogo pledged to organize a democratic vote and vowed not to seek office. However, ECOWAS said the junta must take concrete action.

The regional bloc has put a military force on standby.