A killer armed with "multiple guns" shot nine dead at an American college - ordering students to stand up and state their religion before firing.

The attacker, 26-year-old Chris Harper-Mercer , died in an exchange of gunfire with police in Oregon.

He had body armour and was armed with three pistols, a rifle and five extra magazines but was not thought to have a criminal history.

Harper-Mercer was said to have been born in England before moving to the United States as a young boy.

He was killed after opening fire at the Umpqua Community College in Roseburg on Thursday morning.

Investigators believe he may have been a student there because a receipt found at the scene showed he bought textbooks from the campus bookshop two days before the shooting.

The gunman's father, Ian Mercer, said he was "shocked" and "devastated" by the attack.

Speaking to reporters, he said: "Obviously, it's been a devastating day. Devastating for me and my family.

"I'm just as shocked as everybody at what happened today. I've just been talking to the police and the FBI."

The massacre is the deadliest shooting in the US since nine people died in a rampage at a South Carolina church in June.

:: US Gun Violence: History Of Deadly Shootings

President Barack Obama called for stricter gun control laws in America to stop the violence .

He said "inaction" on gun control legislation makes all Americans "answerable" for the ongoing gun violence.

"We are going to have to change our laws. This is not something I can do by myself," he said.

"I need to have congress and state legislatures and governors who are willing to work with me on this."

Student Kortney Moore, 18, told the News-Review newspaper she was in her class in Snyder Hall when a shot came through a window.

The bullet hit her teacher in the head, throwing him to the ground, before the gunman stormed in.

She said the gunman told people to get on the ground before ordering them to stand up and state their religion .

If students replied that they were Christian, he replied: "Good, you'll see God in a second."

Umpqua student Brady Winder, who was in a nearby class, said they heard a sound like a heavy object dropping.

The 23-year-old said: "Everybody's head turned and looked at each other, trying to just grasp what was happening, and someone said, 'Those are gunshots.'

"We heard people screaming next door. And then everybody took off. People were hopping over desks, knocking things over."

He said he saw a girl swim across a creek while escaping.

Students were patted down by law enforcement officers as they escaped the scene of the shooting to ensure there was no second gunman.

Harper-Mercer's social media profiles featured content supporting the IRA.

According to his profile on a dating site, he is 'mixed race,' a 'conservative Republican,' 'not religious' and lives with his mother.

Joe Olson, the former president of the college, said it has only one unarmed security officer on duty at any time.

The adult-learning college has some 3,300 students and the average age of students is about 38, according to its website.

Agents from the FBI and the Bureau of Alcohol, Tobacco and Firearms are among those who responded to the scene.

According to pro-firearms control group Everytown for Gun Safety, it is the 142nd school shooting since the attack at Sandy Hook Elementary , Connecticut, in December 2012.