African Union officials said they had suspended Mali and would send a mission to the West African nation to assess the situation after a group of mutinous soldiers seized power.
Jean Ping, the AU's chairman, told a delegation that met in Ethiopia's capital on Friday for an emergency peace and security meeting that a mission would deploy to Bamako later the same day.
Ping did not immediately give any details about the mission, but said Mali was going through a "very serious crisis" and that the coup was a big setback for the country and for all democratic efforts across Africa.
Ping's spokesman Noureddine Mezni said that according to AU rules, Mali would be temporarily suspended as a member of the continent-wide body.
The suspension came as Malian rebels vowed to continue fighting amid global condemnation for the coup that toppled President Amadou Toumani Toure's democratically elected government.
The rebels, known as the National Movement for the Liberation of Azawad, said on their website they "will continue the offensive to dislodge the Malian army and its administration from all the towns of Azawad".
Azawad is the name for the rebels' professed homeland in the northern triangle of the West African nation.
Mali's military, citing Toure's government's failure to arm and equip them to fight the Tuareg rebels in the north, seized power on Thursday, drawing condemnation from the UN Security Council, the African Union and ECOWAS, the West African regional block.
The World Bank and the African Development Bank both announced on Thursday they were suspending development aid to Mali before urging "the restoration of constitutional government".
The rebels said the coup had changed nothing and that they would continue fighting for "self-determination and independence," according to a statement signed by their spokesman, Bakaye Ag Hamed Ahamed.
The statement said the rebels had on Thursday seized the town of Anefis on the national highway linking Gao and Kidal - the main cities in the vast desert north.
Quoting residents, the Reuters news agency said bread and fuel were running low in the capital Bamako as mutineering soldiers looted petrol stations and shops and hijacked cars.
Ban Ki-Moon, the UN secretary-general, condemned the coup and called on its leaders "to refrain from any actions that could increase violence and further destabilise the country".
The UN's political chief said there was a link between the uprising against Muammar Gaddafi last year and the Mali coup.
Ethnic Tuaregs who had fought with Gaddafi returned to Mali and joined the Tuareg rebellion against the government, said B Lynn Pascoe, the UN's assistant secretary-general.
"Of course there is a relationship because many of the Tuaregs had gone to Libya because there they could earn more money working in the military," Pascoe told reporters.
On returning to Mali, the ex-Gaddafi fighters and the arms they brought from Libya "clearly added more firepower and drive" to the longstanding Tuareg rebellion in the north of the country.
The presence of the former Libya fighters was "one of the things which fuelled the frustration and the anger of the [Mali rebel soldiers] because they didn't think they were being supported strongly enough in the fight against the Tuaregs," Pascoe said.
Said Djinnit, the UN envoy for West Africa, was among foreign officials in Bamako at the time of the coup, while attending an African Union meeting.
Pascoe said Djinnit was working with West African governments and the African Union to try to end the crisis. A number of African ministers were also stuck in Bamako after the African Union meeting.
The African Union strongly condemned the coup and said it was holding discussions with ECOWAS and other regional actors.
South Africa and Nigeria also condemned the coup, while France announced the suspension of all state co-operation with the country.
"The Malian people aspire to peace, security and democracy. It is essential to restore the country’s constitutional order, political stability and security conditions while avoiding all violence," a statement said.
The European Union on Friday decided to temporarily suspend development operations in Mali as EU foreign ministers called for the return of civilian rule.