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.

The explosion occurred in a parking lot near the campus steam plant around 9:50 p.m. According to 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. According to 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.

At a press conference Friday morning, U of I officials said the experiment was not intended to launch the rocket. University officials said the rocket was 8-12" of galvanized metal pipe.

The FBI was on scene investigating Thursday night, which is routine procedure according to Moscow police. University officials said there is no criminal investigation into the incident at this point.

The blast happened at 9:50 p.m. on Thursday, but the university did not send out an alert through the emergency warning system until about an hour later.

"These situations are fluid, we have to address those," said Dan Ewart, the University of Idaho VP for Infrastructure. "We do want to make sure we get the proper information out. We did that. We'll continue to evaluate our processes too."

He added that the support from campus, the community and law enforcement has not gone unnoticed.

"Any time any part of our Vandal family is injured, we take it very personally," Ewart said.

This story has been updated.