A senior UN official on Tuesday told the UN Security Council that the situation in Mali, where a military coup was staged on March 22, "has taken a turn for worse," according to Susan Rice, the United States ambassador to the UN.

Rice, who holds the rotating council presidency for April, made the briefing while informing the press here on the work program of the 15-nation UN body for this month.

The UN Security Council met behind the closed doors and heard a briefing by Lynn Pascoe, the UN under-secretary-general for political affairs, on the current situation in Mali, which comes under severe sanctions by West African countries and the African Union in the wake of the military coup, according to Rice.

"The humanitarian situation is also deteriorating," said Pascoe.

The council members are united in asking the ruling military leaders in Mali to step down in order to restore the constitutional order in the West African country, Rice said.

Also on Tuesday, the African Union announced targeted sanctions on leaders of armed factions fighting in northern Mali after slapping travel bans and asset freezes on the country's ruling military junta.

West African leaders on Monday slapped crippling sanctions on Mali's new junta following the country's ruling military failed to fully restore constitutional order in line with an earlier directive.

Alassane Ouattara, the president of Cote d'Ivoire who is the current chairman of the 15-nation Economic Community of West African States (ECOWAS), said a complete embargo, including closing borders to trade and freezing access to the country's bank accounts, would come into effect immediately.

Mid-ranking officers, led by army Captain Amadou Snogo, toppled Malian President Amadou Toumani on March 22 in protest of the government's failure to rein in the rebels who are seeking to create a separate homeland in the north.

UN officials said that they are deeply concerned about instability, armed groups and the prospect of widespread food shortages in Mali, where some 200,000 people have fled their homes seeking refuge elsewhere in the region.

UN refugee agency spokeswoman Melissa Fleming said that more than 2,000 fled to Burkina Faso and Mauritania in the past five days alone because of armed groups proliferating around northern communities and other violence since the March 22 military coup.

The World Food Program spokeswoman Elisabeth Byrs said the UN food agency is "particularly concerned" at the prospect of widespread food shortages.