Czech President Milos Zeman was hospitalised Tuesday while predecessor Vaclav Klaus was undergoing tests at the same hospital.
The presidential office didn't immediately comment on Zeman's hospitalization, which was confirmed by Prague's military hospital. Further details weren't immediately given.
An adviser to Zeman told Czech public radio that he was there for a regular check.
Zeman, 76, is a heavy smoker who has suffered from diabetes and neuropathy linked to it. He has trouble walking and has been using a wheelchair.
Klaus was also admitted to the same hospital Tuesday to undergo unspecified tests. He spent time at the hospital last weekend because of high blood pressure, his spokesman told Czech public television.
Klaus, 80, a vocal opponent of the coronavirus restrictions, fell ill with Covid-19 in February but didn't need hospitalisation.