ALGIERS • Algeria's security services have been rocked by the arrest of its anti-terrorism chief and sackings of top officials in recent weeks, as a power struggle intensifies behind the scenes.
The oil-rich North African state has been ruled since 1999 by President Abdelaziz Bouteflika, but concerns have been growing over how much longer he can stay in power.
The 78-year-old was re-elected last year, but appeared only once for the campaign - in a wheelchair, after having had a stroke in 2013.
Experts say he and his allies - especially army chief of staff Ahmed Gaid Salah - are consolidating power for a potential succession battle.
Such a struggle could spark instability in a country already beset by an Islamist insurgency, inter-ethnic violence and a squeeze on public finances from falling oil prices.
Experts say the crackdown has tilted the balance in favour of Mr Bouteflika and General Salah, at the expense of a faction led by the DRS state intelligence service and its chief, Gen Mohamed Mediene, 76.
Political science professor Rachid Tlemcani believes Mr Bouteflika has defeated DRS, which has emerged as a "state within the state".
On Aug 27 came the unprecedented arrest of counter-terrorism chief Abdelkader Ait-Ouarab, also known as Gen Hassan. Until last year, he led an elite DRS unit whose missions included a 2013 assault on a key gas plant after extremists seized it.
Local media reported he was arrested at his home in Algiers and was being held at a military prison 50km south of the capital.
Newspaper El Watan described Gen Hassan, a close ally of Gen Mediene, as "collateral damage" in the power struggle.
Several weeks before, three security chiefs were fired - two are deemed close to Gen Mediene. Known here as Toufik, he has never appeared in public.
The head of the counter-intelligence unit and the chief of presidential security were replaced with little explanation, except for references to an "accident" in which shots were fired at a presidential residence.
As commander-in-chief and defence minister, Mr Bouteflika has the power to sack any security official. El Watan said many were forced to retire in recent months.
"Many other officers, notably those who made names for themselves in the fight against terrorism, found themselves on the list of those eligible for retirement, including some aged 38 to 50," it wrote.
In the past 18 months, DRS has lost many powers - including the right to carry out judicial probes into corruption - and some duties have been transferred to the army.
Also, unconfirmed reports say the powerful GIS Special Intervention Group, a tactical sub-unit of the DRS, has been dissolved.