The BNP is holding a rally before the National Press Club in Dhaka demanding its chief Khaleda Zia be allowed to go abroad for advanced treatment.
The party’s Dhaka South and North units arranged the rally on Sunday morning.
BNP leaders and activists at the rally also demanded the party chairperson’s unconditional release.
BNP Secretary General Mirza Fakhrul Islam Alamgir addressed the rally as the chief guest later in the day.
Members of the BNP’s affiliates, including Chhatra Dal and Jubo Dal, also partook in the protest.
Additional forces have been deployed in the area to maintain law and order.
Khaleda Zia was admitted to Evercare Hospital in Dhaka in the early hours of Saturday after she suddenly fell ill.
Fakhrul on Saturday said the government would be held accountable if anything bad happened to Khaleda Zia.
Stating that Khaleda’s life would be at stake if she could not receive advanced treatment, he renewed the party’s call for allowing her to go abroad for medical care.
“Doctors performed an angiogram on Khaleda Zia and found a blockage in the coronary artery. They then successfully placed a ring there,” he said.
Earlier at an emergency meeting, he said the medical board formed to ensure treatment for Khaleda Zia at Evercare Hospital had decided to perform the angiogram as she had suffered a mild heart attack.
The senior BNP leader urged people to pray for Khaleda Zia’s speedy recovery.
It is the fifth time the BNP chief has been admitted to the hospital since testing positive for Covid-19 in April last year.
Khaleda, who served three times as prime minister, has been suffering from various ailments, including liver cirrhosis, arthritis, diabetes as well as kidney, lung and eye issues.
On February 1, Khaleda returned home after an 81-day stay at the hospital over internal bleeding caused by liver cirrhosis.
The former prime minister was sent to the Old Dhaka Central Jail as a lower court had sentenced her to five years in prison in the Zia Orphanage Trust corruption case on February 8, 2018.
Later, she was found guilty in another corruption case the same year.
Amid the Covid-19 pandemic, the government temporarily released Khaleda from jail through an executive order suspending her sentence on March 25, 2020, on condition she stay at her Gulshan home and not leave the country.