ANTANANARIVO (AFP) - Madagascar's military-backed government sacked a third of the country's regional administrators and replaced them with army brass ahead of a second round of presidential elections, prompting allegations of a partial coup Thursday.

Mr Andry Rajoelina's government appointed five colonels and three generals to run the eight provinces, predominantly in the lawless south of the country where cattle rustling is common.

Mr Rajoelina seized power from former president Marc Ravalomanana in 2009 in a military-backed coup.

The government said in a statement Wednesday that the move affecting about a third of the country's 22 regions was made because of "the candidacy of some regional leaders to legislative elections, recent insecurity and the national political context".

National newspapers accused Mr Rajoelina of forming a military junta.

It is the second round of such sackings. In August the government dismissed seven regional leaders, replacing them with civilian appointees.

On December 20 voters are expected to choose a new president, with many hoping it will put an end to years of political turmoil.

Former defence minister and retired General Desire Ramakavelo told AFP the decision could foreshadow a state of emergency being declared.

"Such a decision is not ideal given the context, on the eve of the second round." Amid international pressure, former Ravalomanana and Rajoelina are not candidates in this year's presidential elections, but their surrogates are in the run-off.

Mr Jean Louis Robinson, Ravalomanana's candidate and Mr Hery Rajaonarimampianina backed by Rajoelina, collected respectively 21 and 16 per cent of the vote in the first round.