Algerian state prosecutors on Monday said they had banned corruption suspects from leaving the country after launching probes into graft and illegal money transfers abroad targeting unnamed individuals.
The moves come amid nationwide protests against President Abdelaziz Bouteflika and follow the arrest of one of the incumbent's key backers, business tycoon Ali Haddad.
Haddad, who Forbes magazine describes as one of Algeria's wealthiest entrepreneurs, was detained overnight Saturday to Sunday at a border post with neighbouring Tunisia, a security source said, without giving a reason for the arrest.
On Sunday, the Algerian authorities also banned all private aircraft from taking off and landing until the end of the month.
The North African state has been rocked by weeks of mammoth protests sparked by Bouteflika's decision in February to seek a fifth term in office.
The veteran leader, who has rarely been seen in public since suffering a stroke in 2013, said last month he would pull out of the race but postponed elections which were due in April.
The concession has done little to halt public ire and hundreds of thousands of people took to the streets of the capital Algiers on Friday demanding the president and his entourage go.
Faced with the persistent anger, a succession of veteran Bouteflika loyalists have sought to distance themselves from the president in recent days.
On Tuesday, armed forces chief of staff Ahmed Gaid Salah called for him to step down or be declared medically unfit.