Seven people have been killed and three others injured in a school shooting on Monday in Oakland, a city in the U.S. state of California, local police said, according to Xinhua.

Police said that ten people were hit in the attack which occurred around 10:30 a.m. local time at Oikos University in Oakland. A suspect has been detained about an hour later in a shopping mall around 4.8 km from the school, but police did not disclose if the suspect was a student at the school.

The police are continuing to search the school building for more victims.

The gunman was earlier described as a Korean man in his 40s with a heavy build and wearing Khaki clothing.

Pastor Jong Kim, who founded the school about 10 years ago, told local newspaper Oakland Tribune that the shooter had previously been a nursing student at Oikos but was no longer enrolled. He was unsure whether the shooter had been expelled or dropped out voluntarily.

Kim said that he did not see the shooting but heard about 30 gunshots.

A witness told the San Francisco Chronicle that a man in her nursing class rose up and shot one person at point blank range in the chest before he started spraying the room with bullets.

The area surrounding the scene has been cordoned off for public safety.

According to the website of Oikos University, it is a Christian school that offers classes like religious studies, nursing and music with an emphasis for students of Korean descent.