An Algerian military tribunal has convicted the nation's long-time counterespionage chief of breaching orders and destroying documents and sentenced him to five years in prison.

The verdict against Abdelkader Ait Ouarabi, best known as Gen. Hassan, fell late Thursday in a closed-door trial in the Mediterranean city of Oran.

Grounds for the charges were not made public, though the Algerian press has reported accusations of arms possession and creating an armed organization.

Hassan said Friday through an attorney, Mokrane Ait Larbi, that he plans to appeal the verdict.

Hassan was forced to retire in 2013 after leading a two-decade war against Islamic extremists. That conflict erupted after the army canceled 1991 legislative elections to thwart a win by an Islamic fundamentalist party. Ensuing violence left an estimated 200,000 dead.