South Africans have prayed for the health of former president Nelson Mandela and anxiously awaited further word about the anti-apartheid leader after he was admitted to a military hospital.
President Jacob Zuma visited Mr Mandela on Sunday morning at the hospital in Pretoria and found the 94-year-old to be "comfortable and in good care", presidential spokesman Mac Maharaj said in a statement.
Mr Maharaj offered no other details about Mr Mandela, nor what medical tests he had undergone since entering the hospital on Saturday.
The church was a centre of anti-apartheid protests and funerals.
"Yes, it really worries us because he is a great person," churchgoer Shainet Mnkomo said as she left an early-morning service. "He did so many things to the country, he's one of those persons who we remember most."
Mr Mandela, who spent 27 years in prison for fighting racist white rule, became South Africa's first black president in 1994 and served one five-year term.
He later retired from public life to live in his remote village of Qunu, in the Eastern Cape area, and last made a public appearance when his country hosted the 2010 World Cup soccer tournament.
Many in South Africa view Mr Mandela, who led the African National Congress to power, as a father figure and an icon of integrity and magnanimity amid the nation's increasingly messy politics.
Inside the church, a stained-glass window depicts Mr Mandela, in a grey suit and blue tie, raising his hands to wave at a crowd.