The family of an Australia doctor and his wife kidnapped in the West African nation of Burkina Faso say they did not know why the couple were abducted or where they were taken.

A family statement on Sunday says surgeon Ken Elliott and his wife Jocelyn disappeared on Friday night.

Authorities do not know if the abductions are linked to the attack on the country's capital by Al-Qaida fighters on Friday night that left at least 28 people dead.

The Burkina Faso government said on Saturday that the couple, believed to be in their 80s, have been kidnapped in the northern town of of Djibo where they have run a medical center for four decades.