Between eight and 10 people have been killed in a shooting 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.
A student was held after the attack. Police said explosive devices were found at the school, 40 miles (65km) south of Houston, and off-campus.
The death toll makes this the deadliest school shooting since the one in February at Parkland, Florida.