Two have been rescued.

The nine tourists are from Odisha, Uttar Pradesh and Tripura.

The tourists were travelling from Lachung to Lachen.

Rescue operations are underway.

Superintendent of Police Sonam Detchu Bhutia said as quoted by Hindustan Times, "Two of the tourists were rescued last (Thursday) night."

"We can see a dead body, but we are not in a position to retrieve it as the river is swollen and the water level is on the rise," Bhutia added.

In a Facebook post, Sikkim Chief Minister Prem Singh Tamang wrote, "I am deeply saddened by the tragic road accident that occurred on the night of 29th May near Chubombu, Mangan District, where a tourist vehicle fell into the Teesta River while traveling from Lachen to Lachung. My heartfelt prayers are with the victims and their families during this extremely difficult time."

"... Our government is fully committed to extending all possible support to the victims and their families. We are closely monitoring the situation and ensuring that every necessary resource is deployed for the ongoing rescue and relief efforts. Let us stand united in this hour of grief and extend our support to those affected."