A gunman opened fire at a Christian college in California on Monday, April 2, killing at least seven people and wounding three after telling former classmates: "Get in line and I'm going to kill you all."

Police said the suspect, a 43-year-old Korean-American, surrendered at a Safeway grocery store several miles away from the scene at Oikos University in Oakland after the deadliest U.S. school shooting in five years.

He was named by police as One Goh, a former student at Oikos, which has links to the Korean-American Christian community.

Police did not immediately offer a motive for the rampage - which came just over a month after a student gunman in Ohio opened fire in a high school cafeteria, killing three students. It was not immediately clear why Goh had left the school.

Witnesses said the gunman entered a reception area of the college at mid-morning and opened fire before walking into one of two classes in session and spraying the room with bullets, Reuters reported.