The gunman was identified as 26-year-old Chris Harper Mercer by local media, which citing eye-witnesses, reported that he allegedly targeted Christians.
An eyewitness said the gunman demanded to know students' religion before shooting them. The police said the motive of the shooter was not known. One professor in the classroom was shot from point blank range.
The gunman, while reloading his handgun, ordered the students to stand up if they were Christians, one of the wounded students, Anastasia Boylan, was quoted as saying by the CNN. The college has about 3,000 students.
"And they would stand up and he said, 'Good, because you're a Christian, you're going to see God in just about one second,'" Boylan's father told the channel.
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A security official said the attacker had body armour with him and was heavily armed, with a large amount of ammunition - enough for a long gunfight.
The Oregon college shooting is the latest in a series of shootings in the US, including at a Charleston church, Sandy Hook school and Oak creek Gurdwara.
Since Obama's re-election in November 2012 there have been 993 mass shooting events in the US, not including Umpqua. Almost 300 of them have occurred in 2015.
A visibly angry Obama, who has so far failed to convince the Republican-majority Congress towards a stringent gun-control laws, spilled out his frustrations, saying "our" thoughts and prayers are not enough.
In the last seven years, Obama has addressed the nation more than a dozen times on nine different shooting attacks.
"Somehow this has become routine. The reporting is routine. My response here at this podium ends up being routine, the conversation in the aftermath of it. We've become numb to this," Obama said.
"Certainly this is a huge shock to our community."
Earlier, authorities had said 13 people died, but later revised the death toll to 10, including the gunman.