Unsolicited phone calls during odd hours

I received 9 calls on the intervening night of 17th May and 18th May to my mobile number +91 98450 17014.  The caller was mute and called me from 97349 87783.  I tried to call this number on the morning of 18th May several times from a different land fone...just answered once...no voice but background noise of a sort of carpentry shop.  Finally, the caller blocked the number....but heard recorded message in Bengali...i dont know bengali although I can identify the language.