A group of people in India went to dinner and ended up in the hospital -- bleeding from their mouths and barfing after being served dry ice ... and being told it was mouth freshener.

This wild scene was captured on video over the weekend out in the city of Gurugram, and it shows five diners at Laforestta Cafe -- where they were collectively puking and spitting out blood all at the same time ... right in the middle of the restaurant, no less.

Local reports say a waiter came by with what the guests were told was a sugar and ice palate cleanser ... but as it turns out, it was actually dry ice -- which led to instant burning.

The effects seemed to kick in right away ... after they put the dry ice in their mouths, they reportedly started bleeding and vomiting in agonizing pain, rinsing their mouths out with water and spitting all over the floor. One guy was throwing up all of his dinner onto the floor.

The cameraman who documented all this didn't end up taking any of the dry ice himself -- he was spared, but only because he was carrying one of their kids ... so he lucked out. Unfortunately, the rest of the adults in his party did take it ... and they suffered badly.

The group was ultimately rushed to a hospital, where they spent 2 days recovering. It was a costly mistake for the restaurant -- the manager was arrested and cops are still searching for the owner, who is said to be on the run. Police are alleging this was an outright poisoning.