The vessel, the last one of the day, run by Surface Transport Corporation, was going from Kakdwip to Kachuberia in Sagar island on Muri Ganga river, district officials said.
Three Bangladeshi oil tankers were going from Kolkata to Bangladesh and the vessel was trying to cross the path of the third one.
The tanker signalled to the vessel several times to let it go first as there could be a collision, but its 'saareng' (captain) ignored the signals and went straight ahead with increased speed, the officials said.
However, several people lost their belongings like mobile phones which fell into the water of Muri Ganga, a tributary of the river Hooghly, the officials said.
A section of angry passengers of the vessel then tried to assault the 'saareng' who was allegedly drunk, but he was saved by other passengers.
After vessel reached Kachuberia, the passengers complained to the authorities and the 'saareng' identified as Subodh Bhuian, was suspended, the officials said.