Algeria's Supreme Security Council decided on Wednesday to close the country's airspace to all Moroccan civil and military aircraft, the Algerian presidency said, less than a month after it cut diplomatic relations with Rabat.
The decision came "in view of the continued provocations and hostile practices on the Moroccan side", the council said.
The closure includes any aircraft carrying a Moroccan registration number, the presidency said after a meeting of the council.
There was no immediate official response from Morocco.
A source at Royal Air Maroc said the closure would only affect 15 weekly flights linking Morocco with Tunisia, Turkey and Egypt.
The source described the closure as insignificant and said the flights could reroute over the Mediterranean.
Algeria late last month decided to cut diplomatic ties with Morocco, claiming "hostile actions" from the kingdom, referring mainly to comments made by Morocco's envoy in New York in favour of self-determination for the Kabylie region.
Algiers also accused Rabat of backing MAK, a separatist group that the government has declared a terrorist organisation.
Morocco said in response that Algeria was unjustified in cutting ties and its arguments were "fallacious and even absurd".
The border between Morocco and Algeria has been closed since 1994 and Algeria has indicated it will divert gas exports from a pipeline running through Morocco, which was due to be renewed this year.