Renegade Malian soldiers have appeared on state television to declare they had seized power in a coup following the government's failure to quell a nomad-led rebellion in the north.

Former colonial power France said it was suspending security cooperation with Mali and urged constitutional order to be reestablished promptly, a call echoed by the European Union.

The coup has been fronted by soldiers of the rank of captain or lower and, if successful, will add a new layer of insecurity to a Saharan region battling Al Qaeda agents and a flood of weapons trafficked from Libya since the fall of Moamar Gaddafi.

The army has for weeks appealed to the government for better weapons to fight the northern Tuareg rebels, now bolstered by heavily armed ethnic allies who fought on Gaddafi's side last year but have returned to Mali.

Members of the newly formed National Committee for the Return of Democracy and the Restoration of the State (CNRDR) read a statement after heavy weapons fire rang out around the presidential palace in the capital Bamako throughout the night.

"The CNRDR ... has decided to assume its responsibilities by putting an end to the incompetent regime of Amadou Toumani Toure," said the group's spokesman, Amadou Konare, who was flanked by about two dozen soldiers.

"We promise to hand power back to a democratically elected president as soon as the country is reunified and its integrity is no longer threatened."

A subsequent statement by Captain Amadou Sanogo, described as president of the CNRDR, declared an immediate curfew "until further notice". Little is known about Captain Sanogo except that he is an instructor at a military training college.

The CNRDR declared all land and air borders shut, but it was impossible to verify whether the mutiny had sufficient support to seal off a country twice the size of France and with seven neighbours. Earlier a reporter said Bamako airport had been shut down by local police rather than renegade soldiers.

While no deaths were reported, an official at the Gabriel Toure hospital in central Bamako said around 20 people had been admitted with bullet wounds, with some in a serious condition.

Government and military sources said the mutineers entered the presidential palace overnight after it was vacated by Toure and his entourage.

A defence ministry source said Toure - a 63-year-old former coup leader due to step down after April polls - was in a safe location but his whereabouts were unknown.

UN secretary-general Ban Ki-moon called for calm and for grievances to be settled democratically in a statement hours before the soldiers said they had seized power.

Jean Ping, head of the commission of the African Union, said he was "deeply concerned by the reprehensible acts currently being perpetrated by some elements of the Malian army".

Reuters