Malawi's vice president has asked the nation to pray for President Bingu wa Mutharika, who was rushed to a hospital in the capital Lilongwe on Thursday.

Diplomatic sources say the 78-year-old leader collapsed earlier on Thursday after a suffering a heart problem. The government did not immediately confirm the illness or the president's condition.

In the hours following Mr. Mutharika's hospitalization, medical sources said he was unconscious.

In an interview with VOA, Vice President Joyce Banda asked Malawians “to stay in prayer and to stay united” as they pray for President Mutharika to recover quickly.

Banda also said she is praying that God protects and strengthens President Mutharika's family.

She did not provide details about his medical condition.

Mr. Mutharika was elected president of Malawi in 2004 and won a second term in 2009.

Critics of the president say he has become increasingly autocratic. Nineteen people were killed last July in anti-government protests.