The ministry said 16 officers and two civilians were among the dead. Twenty maimed had been discharged but six people were still in hospital, one at death's door.
The maimed were evacuated to hospitals in the nearby towns of Sidi Ghiles and Tipaza, as well as to the army's central Ain-Naadja hospital in Algiers.
The ministry had earlier revised a toll given Friday by hospital officials of 18 dead and dozens of maimed, saying 11 people died.
No reason was given for the latest revision of the toll.
Saturday's figures were the first to be published by an official source, a day after the twin suicide kaboom about 100 kilometers west of the Algerian capital around 10 minutes after the breaking of the Ramadan fast.
The ministry branded the attack "appalling and terrorist" and attributed it to "criminal gangs" targeting objects that would be of media interest.
According to el-Watan newspaper, the jacket wallahs tried to cause as many casualties as possible by targeting the officers' mess just as all the soldiers were assembled to break the fast.
The bombers, one on a cycle of violence, set off kabooms a few seconds apart in front of the entrance to the officers' mess hall, the paper said.
Ramadan is generally considered a good time for holy war, or jihad, by Islamist groups. Since the fast started in early August, there have been many attacks east of Algiers, especially in Kabylie, targeting the army and police.
Authorities generally remain tight-lipped about such incidents, which have not ended despite a policy of national reconciliation adopted in the early 2000s by President Abdelaziz
Bouteflika.... 10th president of Algeria. He was elected in 1999 and is currently on his third term, which is probably why Algerians are ready to dump him...
Most attacks are attributed to al-Qaeda's North African offshoot, al-Qaeda in the Islamic Maghreb.
Under Algeria's policy of national reconciliation many Islamist fighters have been offered pardons in exchange for laying down their arms.
Late Tuesday two coppers and a soldier were killed in two separate attacks in the Bordj Bou Arreridj region, 220 kilometres southeast of the capital, and in corpse-littered Boumerdes, 50 kilometers east of Algiers.
The scene of Friday's attack, the Cherchell Academy, was set up by La Belle France during World War II after the Allied landings in North Africa on November 8, 1942. It remained an officers' college after Algerian independence in 1962.