Algeria, Ivory Coast and Morocco, who are among the favourites for the Africa Cup of Nations, have been hit by COVID-19 just over a week before the tournament kicks off in Cameroon.
The Ivorians said players arriving from Europe at their training camp in Jeddah, Saudi Arabia, had tested positive and been put into quarantine by local authorities.
They did not name the players nor state how long they will have to isolate but the rest of the squad would continue with their training, a team statement on Thursday added.
Ivory Coast have been preparing in Saudi Arabia since Monday and are due to stay until Jan. 5, before heading to Cameroon, where they will compete in Group E against Algeria, Equatorial Guinea and Sierra Leone.
Algeria earlier this week said forwards Youcef Belaili and defenders Mohamed Amine Tougai and Houcine Benyada had tested positive at their training camp in Qatar.
They will have to "observe the period of quarantine required by sanitary protocols before re-joining the squad," said the Algerian federation.
On Thursday, Spanish club Barcelona said their Moroccan player Abdessamad Ezzalzouli had also tested positive, putting his participation at the finals in doubt.
Ezzalzouli is only expected to arrive at Morocco’s pre-tournament training camp next week.
All players called up for the Cup of Nations but whose clubs are playing this weekend are allowed to stay at the clubs until Monday in a concession announced last week by the Confederation of African Football.
Usually, players must be released by their clubs to their respective national teams 14 days before the start of the tournament.
(Writing by Mark Gleeson in Cape Town; Editing by Ken Ferris)