Bangladesh Nationalist Party (BNP) secretary general Mirza Fakhrul Islam Alamgir warned on Saturday the government for taking responsibility if anything unwanted happened to the ailing party chairperson Begum Khaleda Zia.

He issued the warnings at a brief rally before road procession in front of the party's central office in the capital's Nayapaltan area.

Dhaka metropolitan city south and north units jointly organised the event demanding the government to release Begum Khaleda Zia immediately and allowing her to receive medical treatment abroad.

Mentioning Begum Zia as a leader for democratic movement not only in South Asia but also Asia he said that Begum Zia has been confined before 2018 national elections till date.

"Still she is in jail. Release her immediately as she is very much ill. The government must take the responsibility if anything untoward happened to her," he said.

He said that such types of cases were also filed against Awami League leaders which were withdrawn.

"This government is illegal and unconstitutional. They (government) have sat on the shoulders of the people over the last 15 years," he stated.