"I have instructed the national gendarmerie to deal with these actions with firmness," said General Ahmed Gaid Salah, the country's strongman since the April resignation of longtime president Abdelaziz Bouteflika.
Gaid Salah said orders had been issued to stop "vehicles and coaches used" to bring demonstrators to the capital by seizing them and "fining their owners".
He made the comments in his first public speech since interim president Abdelkader Bensalah on Sunday announced December 12 elections to resolve the political deadlock gripping the country since Bouteflika's departure.
The army chief has led the push for polls by the end of the year, despite mass protests demanding political reforms and the removal of the former president's loyalists -- including Gaid Salah himself -- before any vote.
Gaid Salah on Wednesday accused "certain parties" of using "freedom of movement as a pretext to justify their dangerous behaviour" and of "falsely claiming to be the voice of the Algerian people".
But the grassroots protests, demanding a full overhaul of the regime, have shown no sign of waning, and key groups demand constitutional changes and other reforms before a legitimate election can be held.
Presidential polls originally planned for July 4 were postponed due to a lack of viable candidates, plunging the country into a constitutional crisis as the 90-day mandate for Bensalah expired in early July.
The army's high command has rejected any solution to the crisis other than presidential elections "in the shortest possible time".