The Santa Fe, Texas, school district and police have said there were explosive devices found in the Santa Fe High school and in a building off campus after this morning's school shooting.

“There have been confirmed reports of explosives found on the campus and off the campus,” Santa Fe Police Chief Jeff Powell said, adding: “That’s our main concern is to keep our community safe". The building has been evacuated after a shooter opened fire and killed at least eight people and injured several others, Chief Walter Braun of Santa Fe Independent School District Police confirmed.

Police have encouraged residents of Santa Fe to exercise caution and call them should they spot any suspicious packages in the area. It is not clear at this time whether any of the explosive devices were detonated and resulted in any of the deaths or injuries. Governor Greg Abbott has confirmed 10 people have died with 10 others injured.

Police identified a suspect, 17-year-old student Dimitrios Pagourtzis, and he is in custody. One other person has been detained but not identified, Mr Abbott said, adding that police are questioning the person.

The governor confirmed during a news conference that the explosive devices included a molotov cocktail that had been found in the suspected shooter's home and a vehicle parked near the school.

The Houston Chronicle newspaper has reported that some of the devices were pipe bombs and pressure cookers, but the exact number and locations of the devices are not known as yet. CNN reported that police are investigating a trailer where the devices may have been assembled.

A local Houston television station said a bomb squad was present at a home on State Highway 6, approximately three miles from the school. The station also reported there were police vehicles present at another home about four miles from the school, but it is unclear if that scene is connected to the shooting at this time.

At least eight students were treated for gunshot wounds, six of whom have been released from hospital. At least one patient is still in fair condition and expected to remain in hospital for several days and three more are being treated in area hospitals.

At least one police officer, John Barnes, was also injured and remains in critical condition. Mr Barnes had retired from the Houston police force before joining school staff.

Explosive devices found in Santa Fe high school and surrounding areas following shooting

The shooting, according to eyewitnesses, began in an art class at around 8am local time. The governor said the suspect said he originally intended to commit suicide but gave himself up and told authorities that he didn't have the courage to take his own life.