At least three people -- including the shooter -- were reportedly shot at a Texas college Tuesday, US media reported but few details were available.
Television footage showed people lying on the ground and at least one person being loaded into an ambulance on the campus of Lone Star College near Houston.
"We know that shots have been fired and we are in a shelter-in-place situation on the campus," Vicki Cassidy, manager of media relations for Lone Star College System, told the Houston Chronicle.
"It's a pretty chaotic scene at this point in time."
The shooter was among three people wounded in the incident at the school's library, KHOU news reported.
Witnesses reported that a male was brought out of the library handcuffed to a stretcher, the station reported.
Dozens of police fanned out across the campus searching for a second suspect on the loose, KHOU said.
A spokesman for the Harris county sheriff's department -- which is handling the event -- told AFP she was not immediately able to provide any information.
The college posted a warning to students on its Facebook page to "SHELTER IN PLACE if you are on campus. IF YOU ARE NOT ON CAMPUS
DON'T GO TO CAMPUS."'
Efren Huerta replied to the post with the comment: "i was walking to my next class. and i heard about 4-6 shots. it happened in the library i think! i just took off running like never before."
Dozens more offered their prayers to the victims and expressed their dismay with comments like "this is crazy!" and "this is sick!"