MOSCOW, Idaho – Three of the four students injured after an explosion on the University of Idaho campus are out of the hospital, officials confirmed to KREM 2 on Monday.

Officials said one student was released Friday, and two others over the weekend. The one student remaining in the hospital is in “good” condition at Gritman Medical Center.

The explosion occurred in a parking lot near the campus steam plant around 9:50 p.m. on Thursday night. Per campus authorities, several students had gathered to test experimental rocket fuel and said the incident was not a bomb threat. Officials said the experiment was not intended to launch the rocket.

The gathered students were part of the Northwest Organization of Rocket Engineers. Per the university's website, the organization is made up of faculty and students who design, build and test rockets. Officials said one faculty member was on scene at the time of the explosion.

Grant Thurman, a University of Idaho student who was at the scene when the rocket exploded, said the group had tested the rocket last week, but made several changes before they tested it again Thursday night.

"We were testing a new fuel design for the rocket engine and we didn't have reason to believe it would blow up or anything because it was a slow-burning fuel, but as soon as it was lit, it blew up," said Thurman.

Students injured in University of Idaho explosion recovering in hospital

MOSCOW, Idaho -- The four students injured in an explosion on the University of Idaho's campus Thursday night were alert and communicating early Friday morning, campus officials confirmed. The injured individuals were transported to Gritman Medical Center after the incident. University officials confirmed the students were all out of surgery and in recovery as of Friday morning.