"The Pakistan army and Urdu-speaking Biharis killed my seven-year-old younger brother Binoy Chandra Das and four-year-old younger sister Minoti Rani Das before my very eyes," said a tearful Shefali Rani Das.
A Birangana of 1971, from Sahebpara area of Lalmonirhat town, Shefali is now 64 years of age.
"My father Charu Chandra Das was a railway driver. [That day] he was driving a train from Lalmonirhat to Burimari station. My mother went to visit a relative in the town. My two younger siblings and I were at home.
"The day was April 4, 1971. Twilight just began to fade into evening. The house was locked from outside. The army and the Biharis broke the lock and entered our house," said Shefali, who was only a teenager back then.
"I cried a lot, but I couldn't do anything for my younger siblings. They later blindfolded me and dragged me out. That day I could recognise Kalu Mastan, a Bihari gang leader from Sahebpara area."
Shefali found out several days later that a member from the local sweeper community was engaged to bury the bodies of her brother and sister, along with bodies of nine other children who were killed the same day, in a mass grave by a bush nearby.
The names of the nine children are Asma Khatun, 7, Jalal Uddin, 9, Helal Uddin, 4, Babu Islam, 12, and Altaf Hossain, 15 (children of railway employee Nasir Uddin Mandal); and Benu Khatun, 5, Sheli Khatun, 7, Hosna Khatun, 9, and Sahidul Islam, 15 (children of railway employee Mohammad Mandal).
On April 4 and 5 in 1971, the Pakistani occupation forces, accompanied by their local collaborators including the non-Bangalees and Bangalee Razakars, went on a rampage against Bangalees to retaliate deaths of Pakistanis during a confrontation that took place at Lalmonirhat Air Base on April 1, between Bangalee and non-Bangalee members of East Pakistan Rifles, according to locals.
Golam Mostafa, 62, son of Mohammad Mandal, said he lost four of his siblings on April 4.
Narrating the massacre, he said he and his father were out of the house that evening. His mother Sulekha Begum was in the house with his four siblings.
The Pakistan army and the Biharis abducted his mother after killing all the four children in front of her and they later shot her dead, Mostafa said. "I later came to learn that my mother's body was also buried in the same mass grave, by the same sweeper.
"I still remember the faces of my siblings and my mother. I can't forget them. We had no chance to bury them according to our custom and we couldn't arrange Janaza for them," he sighed.
In 2009, Golam Mostafa, with the help of locals, demarcated the mass grave of Sahebpara and put up protective walls around it. He continues to hoist the national flag there every day to honour the martyrs.
With members from both Hindu and Muslim communities often gathering before the mass grave at the same time to offer prayers for the souls of their martyred relatives, the Sahebpara mass grave has become the epitome of communal harmony and national unity.
Locals said the site of historic significance deserves to be preserved by the departments concerned of the government.