Ankit (18), Pankaj (25), Chote Veer (40), Ravi (25) and Virendra (30) fell in the molasses tank while trying to take out a bucket which had fallen in it, they said.
Except for Virendra, all others died on the spot, they said, adding, he was rushed to hospital where his condition was stated to be serious.
Police is probing the matter.