MORELIA, Mexico (AP) _ Gas explosions set fire to the ground floor of the eight-story Hotel Presidente, injuring 17 people, officials said.

Leopoldo Espinoza Perez, the fire department's night supervisor, said those injured in Tuesday's blaze were employees and guests, but neither he nor hospital and Red Cross spokesmen could say if any were foreigners.

Six men and three women remained hospitalized with first- and second-degree burns Tuesday night at the Civil Hospital, two of them in serious condition, Juan Manuel Vargas, the doctor on duty said.

Three were being treated at the Social Security hospital, one of whom was in serious condition, said Blanca Ponce, a medical assistant. Five others were treated and released.

Hernando Hernandez, a Red Cross rescuer, said 10 other people were rescued and needed no further medical attention.

The fire began in the colonial-style hotel at 1:40 p.m. (3:40 p.m. EDT), Espinoza Perez said.

''It was an explosion. People there said they were filling gas tanks and apparently they were soldering a tank on the ground floor to repair a leak,'' he said.

Some people escaped from a fifth or sixth floor window by sliding down ropes passed to them by rescue squad members and firemen on the roof, he said.

He said the gas tanks were in good condition and the soldering apparently was on a boiler or other equipment.

The explosion was in the area of a bar-night club, he said.

''All the installations downstairs were damaged - the bar, nightclub, lobby, storage area, kitchen, restaurant, but only two of the rooms, which were nearby on the ground floor,'' he said. ''The rest was not damaged, thank goodness, because we got there in time.''

He said the hotel manager, Maria del Carmen Castel Contreras, was so shaken by the fire that she could not tell them how many people were registered at the time. The government news agency Notimex said it has 32 rooms.