Seven people were killed when a gunman opened fire at a Christian university in California on Monday.

The alleged killer has been named as 43-year-old Korean American, One L Goh. He is reported to have entered a classroom and ordered students to line up against a wall during a nursing lecture at Oikos University, in Oakland.

Goh then opened fire on classmates before exiting the classroom and shooting indiscriminately in other parts of the building.

The attack happened at 10:33am local time. Police SWAT teams arrived soon after and locked down the area.

Another three people were injured in the shooting at the private Korean Christian university.

Goh was arrested shortly after in the parking lot of a Safeway store in the town of Alameda, five miles from the scene of the killings.

According to reports, Goh was recognised by students as a former student who had not attended classes for several months before showing up on Monday morning.

Oikos University is affiliated with a Korean-American church, Praise to God Korean Church, and is situated in a commercial and industrial part of East Oakland close to the city’s international airport. There are reportedly many Korean-American businesses in the area.

Oakland’s police chief, Howard Jordan, told reporters that Monday’s shooting was a “senseless” and “unprecedented tragedy”.

California Governor Jerry Brown, who served as Oakland's mayor from 1999 to 2007, described the killings as "shocking and sad".

A statement issued by his office said: "Our thoughts and prayers go out to the victims, their families and friends and the entire community affected by this senseless act of violence.”

A memorial service is being held on Tuesday evening at the Korean Methodist Church.