A brief statement read over state television on Wednesday said that a new "state council," in what appears to be its euphemism for a military junta, was formed under the leadership of the head of the presidential guard, General Muhammad Ould Abdel Aziz.

Abdel Aziz was among other senior generals, including army chief General Muhammad Ould al-Ghazwani, whom President Sidi Ould Cheikh Abdallahi had replaced earlier in the day, and the coup was the swift response that Abdallahi apparently did not calculate.

The statement, read by the information minister after troops seized control of the radio and television station, declared Abdallahi's dismissal of the officers as null and void, in a clear sign that the president's decree had prompted the coup.

Abdallahi came to power less than six months ago as the first democratically-elected president in the desert northwest African country after a transition ruled by a military junta, which included these two generals that deposed the former president in another bloodless coup in August 2005.

But the president, who has been detained in an unknown location, had come to power with the support of the military, and Mauritanian analysts say it was obvious that Abdallahi had been toppled because he attempted to distance himself from the army and strip it of its political clout.

The president's aides said that Abdel Aziz had led the coup, along with the army chief and the head of the national guard, in a rebellion against Abdallahi's decree.

They added it was within the authority of the president, as commander-in-chief, to make such decisions and condemned the coup as one against democracy and the constitution.

Yet, there was no resistance to the coup in the streets and people went about their normal daily lives; perhaps because the country has been hit by a long series of military coups since its independence from French colonialism in 1960.

But the airport has been closed down for an indefinite period "until the new authorities get organized," according to AFP, quoting an unidentified source.

Independent commentators say the coup was the final blow in a power struggle that had plunged the country into a political crisis in recent weeks, putting the president on a collision course with parliament, political parties and the "untouchable" military.

Analysts suggest the president had sacked these generals for instigating Monday's mass withdrawal of some 50 members of parliament from the ruling Adel Party, a bloc of independent figures that Abdallahi, who won the election as an independent, had formed.

The walkout came after the president last month threatened to dissolve parliament when MPs filed a motion of no confidence in his new government, but the government resigned instead and another was formed.

Some of the president's critics accuse Abdallahi, his family and friends of corruption and leading the country of 3.1 million people into greater poverty.

Mauritania, one of Africa's newest oil producers, imports more than 70 percent of its food and has been hard hit by the global food crisis.

Nevertheless, most politicians were dismayed that the country's players players had resorted to a military coup as their solution to the political crisis; and so soon after Mauritania, a former French colony, began a democratic process with an election that was hailed as a model for democracy in the continent.

While some opposition politicians sought to defend the coup as a "military intervention to protect democracy, the constitution and reforms," others, including the president's critics, warned that the return of military rule was a serious setback for the young democracy.

Although it was not immediately clear whether the new "state council" would dissolve parliament or crack down on constitutional institutions and political parties, many analysts predicted the military would take the country back to the pre-democratic era.

Critics say the president should have avoided a confrontation with the military leadership, which they say had tacitly remained in power and bet on Abdallahi to remain their "puppet president."

He should have expected such a reaction from an institution that had brought him to power and had enough clout, and weapons, to remove him from the presidential palace, they add.

Some analysts suggest that Abdallahi had probably not taken a military overthrow into consideration, because he thought the days of coups d'etat were over and that the army would take into account the international community's rejection of such a development.

The African Union and European Union both condemned the coup in Mauritania, but it was too soon to predict whether an international outcry or pressure would push the army to revoke the move and seek to resolve the country's political crisis without force.