Authorities believe a couple attempting to extract oil from hashish likely caused an explosion that gutted part of the Heritage Inn Sea World Hotel.
Authorities responded to a fire reported at the three-story building shortly before 11:15 a.m. Several people called 911 and said there was an explosion and that people were running outside screaming, police said.
Flames spread from the second floor, but the blaze was mostly under control within minutes.
The victims were rushed to a local hospital for burns injuries. Police said a 22-year-old man who was in the room where the explosion occurred suffered serious injuries. Another woman, who was in the room, also was injured, as well as a man in a nearby room.
Several boxes containing canisters of butane were found inside the room.
The Associated Press contributed to this report.