More than 900 members of Jamaa Islamiya, the Islamist group in Egypt, including its founder, were freed on Tuesday, the interior ministry has said.

The members, some of whom had been imprisoned for more than 20 years, were released in groups over the past 10 days, a ministry official said.

Najeh Ibrahim, one of the heads of the organisation, was among those released, the official said.

Jamaa Islamiya merged in the late 1970s with another Islamist group, Al-Jihad. They are held responsible for planning and carrying out the assassination of Egyptian president Anwar Sadat in 1981.

Jamaa was also responsible for a wave of violence across Egypt in the 1990s, notably a November 1997 attack at Luxor that killed 58 people, most of them foreign tourists.

The group has, however, claimed to have moved away from violent tactics, and published a book in 2003 explaining its ideological shift.