A student opened fire at a high school in the US state of Texas today, killing at least 10 people, mostly students, in the latest such incident in the country.

The incident took place at Santa Fe High School in the city of the same name, located about 50 kilometers southeast of Houston. An unidentified law enforcement officer was shot, but sources said he was "clipped" and was not seriously injured.

At least 10 people were killed in the gunfire, Houston Chronicle quoted federal and county law enforcement officials have confirmed. Harris County Sheriff Ed Gonzalez said a majority of those that were killed in the shooting were students. He said that the two people who were taken into custody, including the person believed to be the gunman, are students at the school.

A search of the school is ongoing, Gonzalez said. He said he has no information about explosives being found at the scene. Several other students were injured in the shooting.

This is the third school shooting in the past seven days, and the 22nd since the beginning of the year in the US.

Trump says early reports not looking good "Unfortunately, I have to begin by expressing our sadness and heartbreak over the deadly shooting at Santa Fe High School in Texas," Trump said Friday from the East Room of the White House. "This has been going on too long in our country. Too many years. Too many decades now."

Trump said federal authorities are coordinating with local officials.

"We grieve for the terrible loss of life and send our support to everyone affected by this absolutely horrific attack," Trump said.