'Amar Ekushey' or the immortal 21 (February), which marks the day of laying down lives for upholding the right to speak mother tongue, is being observed in Bangladesh and elsewhere today (Thursday).
The National Martyrs' Day has also been recognised as the International Mother Language Day by the UNESCO.
The nation pays tributes to the martyrs of the 1952 historic language movement which eventually contributed to the birth of Bangladesh as a independent country.
The theme of this year's International Mother Language Day is "Indigenous languages matter for development, peace building and reconciliation", reports UNB.
Walking barefoot to Dhaka’s Central Shaheed Minar with wreaths and flowers singing 'Amar bhaiyer rokte rangano Ekushey February', people pay their respect to the heroes of the language movement who sacrificed their lives for achieving the recognition of Bangla as the state language of erstwhile Pakistan.
President Abdul Hamid and prime minister Sheikh Hasina have issued separate messages on the occasion.
In his message, the president said, "I extend my warm congratulations and sincere felicitations to all multilingual people of the world along with Bangla-speaking people."
The prime minister, in her message, said the greatest Ekushey is the symbol of grief, strength and glory in the life of every Bangali.
"I pay my deep homage to the memories of the martyrs. I also pay my deep respect to the greatest Bangali of all time, father of the nation Bangabandhu Sheikh Mujibur Rahman who had led the language movement and all other language veterans," she said.
On 21 February 1952, students and the common people in Dhaka took to the streets in protest against the then Pakistani government's denial of Bangla as the national language and imposition of Urdu as the only official language of Pakistan.
Salam, Barkat, Rafiq, Jabbar and a few other brave sons of the soil were killed in police firings on this day in 1952 when students came out in a procession from the Dhaka University campus breaching section 144 to press home their demand for the recognition of Bangla as a state language of then Pakistan.