Dhaka North City Corporation Mayor Annisul Huq, undergoing treatment in a London hospital since August, has been taken back to the intensive care unit.
Family members requested all his admirers and well-wishers to pray for his quick recovery.
Annisul has been suffering from a neurological ailment (dizziness and lack of balance) for some time.
He was admitted to a neurology hospital in central London on August 13 before being diagnosed with cerebral vasculitis.
Later, his condition improved and he was shifted to a regular bed.