There were no victims in the fire in the city's centre with bars and restaurants, Xinhua quoted Eliezer Eugarrio, chief of Leon's Fire Brigade (DGB), as saying in a press conference. Leon is located 93 km west of Managua.
Eugarrio said the fire occurred at 5:45 a.m. and firefighters controlled the fire an hour later despite lack of enough water pumps.
"We are working together with the police to find out the cause of the fire" so investigations may continue, he said.
Eugarrio said the fire destroyed three bars and affected another bar and other property.
Assaff William Schick, owner of El Bar-baro, was quoted as the economic losses were estimated at between $120,000 and 150,000.
A witness said he was in his home in El Sagrario neighbourhood, when he heard a loud blast that came from El Bar-baro and he immediately noticed smoke and fire.