The victims all died from inhaling fumes at the 22-storey Leogrand Hotel and casino, regional health minister Zaal Mikeladze said.
The cause of the blaze, which took hours to extinguish, is not clear.
More than 100 people were evacuated from the hotel by emergency services.
Among those being treated are three Turks and an Israeli, a spokesman for the Batumi University Clinic said.
Earlier, officials said 12 people had died.
Formal identification of the victims is said to be under way, but an interior ministry statement said one Iranian and 10 Georgians were killed in the blaze.
The statement also said that those injured were taken to hospital in a stable condition.
The hotel was due to host the Miss Georgia beauty pageant on Sunday. Officials said none of the 20 contestants, who were reportedly staying in the hotel, were injured.
The country's Prime Minister Georgi Kvirikashvili diverted to Batumi on the way back from an EU summit instead of travelling to the country's capital Tbilisi after he learned of the fire, according to a post on his official Facebook page.
In a later post he offered his condolences the families and promised an investigation to find the fire's causes.
Georgia fire: Black Sea resort hotel blaze leaves 11 dead
25 November 2017
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A fire at a hotel in Georgia's Black Sea resort has killed 11 people and injured 21 more, the Georgian interior ministry has said.
