Several military officers are said to have been arrested in the Mauritanian capital, Nouakchott.
Ould Taya himself came to power in a coup
The government has not commented on the reports which link the detentions to a possible coup plot against President Maaoya Sid'Ahmed Ould Taya.
President Taya survived a coup attempt in June 2003 which sparked off days of fighting in the capital.
The capital is reported to be calm, but some new secuity measures. Troops have also been confined to their barracks.
Sources have been talking about 18 officers being
arrested and appear to be suggesting the
involvement of Islamists.
Some 120 soldiers are still being held in prison awaiting trial following the failed coup last year.
President Taya took power in a bloodless coup in December 1984 and has been re-elected three times since.