The jeep was taking back a marriage party from Kharva village in Uttarkashi to Lambgaon Abki village in Tehri district late last night, he added.
The driver lost control near Chulikhet and the vehicle fell into a river killing five persons on the spot and leaving as many injured.
One person succumbed to injuries while undergoing treatment at the Uttarkashi district hospital, District Magistrate Ashish Chauhan said.
The deceased included two brothers - Bir Singh (53) and Balbir Singh (42), he said.
Operations continued late in the night to recover the bodies and rescue the injured, he added.
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