Speakers demanded that the authorities concerned declare November 12 'Upokul Dibas' (Coastal Day) to remember the victims who were killed in a devastating tidal surge on this day in 1970.
They made the demand at the programmes organised in Barguna and Patuakhali to commemorate this day.
Over 10 lakh people of coastal areas were killed in the disaster.
To recall the victims, various programmes, including lighting of candles and discussions, were held in the two coastal districts yesterday and the day before.
In Barguna, local journalist Arifur Rahman on Sunday arranged candle lighting programme at Shuvo Sandhya sea beach in Taltali upazila to mark the day. People from all walks of life took part in the programme.
The government should declare the day as 'Coastal Day to remember the victims, said organiser Arif.
Meanwhile, local organisation Upokulio Unnayan O Gobeshona Forum in Patuakhali's Galachipa upazila yesterday demanded declaration of November 12 as 'Upokul Dibas' (Coastal Day).
Sankar Lal Das, convener of the organisation, submitted a memorandum to the upazila nirbahi officer (UNO) for forwarding to the disaster management and relief minister.
They observed various programmes, including candle lighting and discussions, in Patuakhali town on the occasion.
People from all walks of life, including journalists and public representatives, joined the programmes.
A procession was brought out in the upazila headquarters marking the day. Kalapara Press Club organised the programme.
Later, a discussion was held at the press club. Jibon Kumar Mondol, vice president of Kalapara Press Club, presided over the meeting.