The incident took place at around 6.30 pm when state tourism department recognised cruise vessel was ferrying the passengers in the river, they said.
"The cruise vessel developed a technical snag and got drifted in the water. It dashed against the casino vessel which was anchored," a police official said.
Marine Police were rushed to the spot who used ladder to shift the passengers from cruise ship to the casino and then ferried them to the shore in small boats, he said.