The Health Ministry in Algeria said a 53-year-old woman and her 24-year-old daughter tested positive for the virus.
It said they live in the city of Blida, some 50 km south-west of the capital, Algiers.
The ministry said they recently hosted a man, 83, and his daughter visiting from France, who were tested positive for coronavirus after their return to France, prompting the health authorities in Algeria to test the hosts.
Only one case had been previously reported in Algeria.
Meanwhile, Egypt’s Health Ministry said a foreigner has tested positive for the new coronavirus, becoming the second case in the country.
The ministry did not reveal the person’s nationality.
It added that the first person has recovered and has been released from the isolation hospital.
Nigeria is the third country in Africa that has reported a confirmed case of the new coronavirus.
Some afflicted develop the pneumonia-like disease Covid-19, which seems to be especially deadly for those with pre-existing lung problems.