Harris County Sheriff's Maj. Armando Tello said authorities had detained a person of interest. He did not provide any details about the people who were wounded, such as whether they were students or included the person who was arrested.
Authorities thought there could be a second shooter, according to a law enforcement official in Washington who spoke on condition of anonymity because he was not authorized to discuss the ongoing case.
The school's official Twitter feed said the shooting was between two people and that the situation was under control. It had issued an alert on its website earlier, telling students and faculty to take immediate shelter or avoid the campus.
Aerial footage from local television stations showed police cars and ambulances parked on the Lone Star College System campus about 20 miles north of downtown Houston. Emergency personnel could be seen tending to people on stretchers, while others ran from a building led by officers.
Mark Smith, spokesman for the Harris County Emergency Corps, said four people were taken to two hospitals. He said at least two had gunshot wounds, and one appeared to have had a heart attack related to the shooting. He said one was in critical condition.
Relatives identified Jody Neal, 24, as one of the people who was shot and said he was taken to Harris Health Ben Taub Hospital Emergency Center with gunshots in his arm, stomach and leg.
“He was sitting in the study room. There (were) three people on the computer and a guy walked up the stairs and opened fire on him,” Stacy Neal, Jody's sister, told KPRC-TV. “They said it was just one guy that came in with a gun.”
Other students said they were studying or waiting for classes to start when they heard gunfire about 12:30 p.m.
“I didn't think they were shots,” said Daniel Flores, 19. “It sounded like someone was kicking a door.”