Dec 31 (Reuters) - Cameroon"s football federation said four of their players have tested positive for COVID-19, with the Africa Cup of Nations hosts set to kick off the tournament against Burkina Faso in just over a week"s time. Pierre Kunde Malong, Jean Efala, Michael Ngadeu Ngadjui and Christian Bassogog had been under observation since Wednesday due to "strong suspicions" and will continue to quarantine apart from the group, the Cameroon Football Federation said on Thursday. Algeria, Ivory Coast and Morocco, who are among the favourites for the Cup of Nations, have been also been hit by COVID-19 in the build-up to the tournament. Cameroon, who have won the Cup of Nations five times, will compete in Group A with Burkina Faso, Cape Verde and Ethiopia at the tournament, which gets underway on Jan. 9.