(CNN) A teacher was killed and six other people injured when an 11-year-old student opened fire Friday at a private school in the northern Mexican state of Coahuila, officials said.

The shooter, a sixth-grader armed with two guns, also died, said Adelaido Flores, the regional coordinator for public safety in Coahuila, near the Texas border.

Coahuila Gov. Miguel Angel Riquelme told reporters that classmates said the boy was generally well behaved but voiced a strange warning before his rampage on Friday.

"He told some classmates, 'Today is the day,' " Riquelme said.

Shortly after 8 a.m., the student asked to use the restroom. After about 15 minutes, the teacher went to look for him and found him leaving the restroom with weapons in hand, the governor said.

Read More