President Maaouya Ould Sid'Ahmed Taya being greeted by Sultan Ibn Abdul Aziz

The United States Wednesday urged a return to constitutional rule in Mauritania after military officers there said they had overthrown President Maaouya Ould Sid'Ahmed Taya. The United Nations and African Union have made similar appeals.

Officials here acknowledge that President Taya's 20-year tenure has been marred by human rights violations and other issues. But they say a military coup is not the answer to the country's problems and are urging, as are the African Union and United Nations, a return to constitutional rule.

At a news briefing, acting State Department Spokesman Thomas Casey said the situation in the Mauritanian capital, Nouakchott, was unclear and that the U.S. embassy there remained open and was monitoring events.

He said the United States joins with the AU in condemning violence, and calls for a peaceful return to order under the country's constitution and the established government of President Taya:

"He is the established constitutional president of Mauritania," he said. "We have dealt with him under those terms, and certainly there is no reason in our mind for any kind of extra-constitutional action."

President Taya was out of the country when troops seized control of key sites in the capital, including the national television and radio stations.

An announcement by a group calling itself the Military Council for Justice and Democracy said it had seized power, and wanted to put an end to what it called the totalitarian practices of Mr. Taya's government.

Market in Mauritania shanty town

The State Department said earlier this year in its global human rights report that the Mauritanian government's record was poor, and included cases of abuse by security forces and restrictions on freedoms of speech, association and religion.

However, a senior diplomat who spoke to reporters here said the ouster by force of arms of an elected civilian leader, even one with problems, is not something the United States is going to support.

There were similar comments from the African Union, which said any unconstitutional change in government is not acceptable. U.N. Secretary-General Kofi Annan said he was deeply troubled by reports of the coup.

President Taya himself seized power in a bloodless coup in 1984, though he was elected to office three times, most recently last November in an exercise opposition leaders said was marred by fraud.

Spokesman Casey said the U.S. embassy in Nouakchott remained open but with reduced staffing, and said it had issued an advisory to the small American community in Mauritania to remain home and to take security precautions.

The senior diplomat said embassy officials have had contacts with members of the government, but that he was unaware of any contacts with the military or the council that said it had assumed power.