The incident took place at Sonadanga residential area of Khulna on Wednesday around 12:15 pm.
Khulna Metropolitan Police Deputy Commissioner (South) Mohammad Tajul Islam confirmed the incident to the BBC.
He said that the boy, who was seriously injured in the thrashing, was taken away by the army and said that he was not sure whether the boy had died or not.
However, even after calling the numbers of several officials including the spokesperson of the army camp in Khulna, their statements were not received.
Locals said that Utsav Mandal belongs to Hindu religion.
Meanwhile, it is not clear what exactly was written in the Facebook status.
The police said that a case will be filed in this case on Thursday, the process is going on.