A gunman opened fire on Thursday at an Oregon community college, killing 13 people in an act of violence strongly condemned by President Barack Obama.

Thirteen people were killed in the incident at Umpqua Community College and about 20 others were wounded, according to Oregon Attorney General Ellen Rosenblum.

The shooter — a 20-year-old man — died after exchanging gunfire with law enforcement, officials said. It was not immediately clear if he was included in the number of deceased Rosenblum provided.

Oregon Gov. Kate Brown said in a statement that it is "still too early to know all of the facts," but stressed the state's top priority is treating injured victims and securing the campus. Authorities did not immediately give any details on a motive but said they were investigating.

In a somber press conference, Obama expressed both support for the victims and incredulity that Americans continue to die in mass shootings. He renewed his call for stronger gun controls to help stem the violence.

"Somehow, this has become routine. The reporting is routine. My response here at this podium ends up being routine," he said in a prepared statement. "We've become numb to this."

Opponents, many of which are members of the Republican-controlled Congress, however, strongly oppose new measures. They argue gun control legislation does little to prevent incidents of violence.