Between eight and 10 people have been killed in a shooting by a student at a Texas high school, say police.
Harris County Sheriff Ed Gonzalez told reporters the majority of the dead at Santa Fe High School were students.
The suspect in custody has been identified as 17-year-old Dimitrios Pagourtzis, according to CBS News.
Police said that explosive devices had been found at the school, which is 40 miles (65km) south of Houston, and in surrounding areas.
Santa Fe Police Chief Jeff Powell said: “There have been explosive devices found inside the high school, and in the surrounding areas adjacent to the high school.”
He advised residents to be aware of any suspicious objects they find.
“Do not touch any items that look out of place,” he said, warning residents to immediately call police.
Santa Fe school police officer John Barnes has been named among the injured.
Mr Barnes is currently in critical condition and undergoing surgery, according to local media.
Two hospitals south of Houston said they had received nine patients from the school shooting.
Clear Lake Regional Medical Center said it admitted seven, and Mainland Medical Center received two.