The flames that spread rapidly through the market at the Nusseirat refugee camp also injured 58 people, of whom 14 were in critical condition, according to the ministry. The dead included six children and two women.
The fire burned a bakery, several stores and dozens of stalls and vehicles. The Interior Ministry said initial findings by investigators indicated a gas leak at the bakery might have started the fire.
Meanwhile, Gaza's Hamas rulers announced that Emir Tamim bin Hamad Al Thani of Qatar had allocated $2 million in compensation for damage and losses the fire caused.
With a population of nearly 2 million, the Gaza Strip is one of the world's most densely populated areas. It's a 360-square-kilometer (139-square-mile) corridor of land, sandwiched between Israel and Egypt. The two countries imposed a blockade on the territory when the militant Hamas group seized it in 2007.
The blockade, three devastating wars with Israel and dozens of skirmishes have damaged Gaza's infrastructure.