Authorities have detained one suspect at the campus in Cypress, Texas -- so far the only suspect at this point, a sheriff's spokesman told reporters Tuesday afternoon.
Student Maya Khalil, 19, was in class in the campus' health sciences building when the incident happened, she said. She managed to take photos of the chaotic scene as it unfolded.
"It was really scary," Khalil said.
The school was on lockdown Tuesday afternoon while authorities combed the campus to ensure no other injured people or attackers were there, Harris County sheriff's spokesman Alan Bernstein said.
It wasn't clear whether all of the injured people were stabbed, Bernstein said.
"It's possible other people were running away" and became injured that way, Bernstein said.
Four people were taken to a hospital by helicopter, authorities said. The conditions of the victims weren't immediately available.
The four flown to a hospital "were in a dire enough situation that they were taken out on helicopters," Bernstein said.
Bernstein said it will take time for authorities to go through the campus and "make sure there (is) not another suspect or suspects."
"I do believe the confrontation was limited to a few (classrooms) or just one classroom -- not anybody roaming around and getting into a large number of areas," Bernstein said.
Details about what led to the incident weren't immediately released.
"Stay away from the area. Seek shelter in a secure location until the incident is resolved," the school posted on its website.
Tuesday's incident comes more than two months after three people were wounded in a shooting at a different Lone Star College campus -- the North Harris campus in Houston.