Three prisoners accused of belonging to an Al Qaeda-linked Algerian militant group escaped Thursday from a jail in Mauritania's capital, officials said.

The three men were imprisoned on suspicions of membership in the Salafist Group for Call and Combat insurgency, which has launched attacks inside Mauritania. They escaped around 1200GMT from a prison in Nouakchott, said top justice official Limam Ould Teguedi.

CountryWatch: Mauritania

An investigation has been launched into the circumstances surrounding their flight, he said.

Police Lt. Mohamed Lemnie said the three were imprisoned in April 2005 by the regime of ousted ex-President Maaouya Sid'Ahmed Ould Taya, who jailed many political opponents on what Mauritanians felt were trumped-up terrorism charges.

Mauritania's new leader, Col. Ely Ould Mohamed Vall, released dozens of those prisoners after taking power in a bloodless August coup, but kept about two dozen suspected militants behind bars, including the three that fled Thursday.

On June 4, a guerrilla raid on a remote army post in northern Mauritania left 15 soldiers and nine attackers dead. Algeria's Salafist Group for Call and Combat, which is on the U.S. list of terrorist organizations and has vowed fealty to Al Qaeda, purportedly claimed responsibility for the raid in an Internet statement.

Some of those jailed by Taya's regime were accused of setting up local terror networks whose supporters allegedly trained with the Salafists, who favor a strict Islamic state in Mauritania's northern neighbor, Algeria.