Dhaka North Mayor Annisul Huq is being treated at the intensive care unit of a London hospital.
Bangladesh High Commission's Minister (press) Nadeem Qadir said he has been diagnosed with cerebral vasculitis. "His wife Rubana Huq has asked all to pray for his recovery."
Cerebral vasculitis is inflammation of the blood vessel wall involving the brain.
According to Qadir, the mayor has been ill for quite some time, but doctors in Bangladesh could not identify his problem. "The prime minister spoke with Rubana Huq over phone on Tuesday and wished his early recovery."
On Jul 29, Huq went to London to visit his daughter.
Abraul Hasan, an aide to the mayor, said Huq's daughter has given birth to a child on Aug 8.
"He was supposed to come back on the 14th and join the National Mourning Day programmes the next day. The last time we spoke was on the night of the 13th, when he said he's not flying back to Dhaka as scheduled earlier," Hasan said, reports bdnews24.com.
A person close to the family said the mayor has been unwell for quite some time.
"On Friday, he went to a London hospital as he was not feeling well. During the diagnosis, he fell unconscious. Doctors found inflammation of the blood vessel wall in his brain. He is being treated at the ICU," he said, preferring anonymity.