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

The soldiers of the newly formed National Committee for the Restoration of Democracy and State read out a brief 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 Amadou Konare, spokesman for the National Committee for the Restoration of Democracy and State.

"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," said Konare. A subsequent statement declared an immediate curfew "until further notice".

The statements made no reference to the whereabouts of Toure, who, for the past decade, has presided over one of the more stable governments in West Africa and was due to step down after elections scheduled for late next month.

However, the gold- and cotton-producing nation has struggled to contain a northern rebellion launched late last year by local Tuareg nomads, joined by heavily armed fellow Tuaregs returning from Libya after fighting for Muammar Gaddafi.

Greater insecurity

The rebellion, in which dozens have been killed and nearly 200,000 civilians have fled their homes, has added a new layer of insecurity to a region where al-Qaida allies have carried out a spate of kidnappings of Westerners.

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 continental grouping, said he was "deeply concerned by the reprehensible acts currently being perpetrated by some elements of the Malian army".

Sporadic heavy weapons and tracer fire rang out in Bamako through the night, and the mutineers, who say they lack arms to face the separatist insurgency in the Sahara, temporarily forced the state broadcaster off air.

Reuters