Zambia's founding father and former president Kenneth Kaunda has been admitted to hospital, his office said Monday.
In a statement, it said Kaunda, 97, "has been unwell and was admitted to... Maina Soko Medical Centre," a military hospital in the capital Lusaka. It gave no further details.
Kaunda ruled Zambia for 27 years, taking the helm after the country gained independence from Britain in October 1964.
The statement said Kaunda was asking Zambians and the international community to pray for him "as the medical team is doing everything possible to ensure that he recovers".
Initially a popular leader, Kaunda became increasingly autocratic and banned all opposition parties.
He eventually ceded power in the first multi-party elections in 1991, losing to trade unionist Fredrick Chiluba.
While in power he hosted many of the movements fighting for independence or black equality in other countries around the region, including South Africa's African National Congress (ANC).
Later in life he regained stature as one of Africa's political giants, helping to mediate crises in Zimbabwe and Kenya.
Affectionately known as "KK", Kaunda was the head of the main nationalist party, the left-of-centre United National Independence Party (UNIP).
Also nicknamed "Africa's Gandhi" for his non-violent, independence-related activism in the 1960s, he charmed mourners at Nelson Mandela's burial in December 2013.