Out of the 30 injured, 20 people are reported to be in a serious condition, they said.
A short circuit in one of the AC ducts of three-storey Hotel Wanton House apparently led to the massive blaze at the premises, located in Sector 26 on the Palm Beach Road of Vashi, they said.
"We got a call at around 5 AM that a fire has broken out in the hotel which also has a considerable number of foreigners staying in it. Following the call, we pressed eight fire engines and water tankers into service to douse the flames at the hotel," an official from Navi Mumbai Municipal Corporation told PTI.
Fire brigade officials said the blaze was brought under control after over four hours of hectic fire-fighting.
"The operation that began at 5 AM took more than four hours to end. A lot of time was required to evacuate those trapped in the hotel and bring them to safety. Since the fire was a major one, getting the trapped to safety amidst the smoke was an uphill task. We also did not have a blueprint of the hotel initially which added to the confusion," a fire official from the Navi Mumbai fire brigade said.