At least 13 people have died after a gunman opened fire on the campus of Umpqua Community College in southwest Oregon at 10:38 a.m. local time today, injuring as many as 20 other people, reports the Associated Press.

Douglas County Sheriff John Hanlin told reporters the gunman was killed while exchanging gunfire with law enforcement officials, according to NBC News. Police are currently investigating social media posts the suspect allegedly made Wednesday night that may have indicated his plans, notes CNN.

In a short address to media this afternoon, Oregon Gov. Kate Brown announced that the gunman was a 20-year-old male but declined to offer additional details about the shooter's identity or possible connection to the school, according to the AP.

"Today is heartbreaking for Umpqua Community College, the greater Roseburg community, and all of Oregon," Gov. Brown said in a statement before she addressed the media. "My heart is heavy as details of today's shooting become available. While it is still too early to know all of the facts, the effects of an incident such as this one are long-lasting. Please join me in keeping the victims and their families, as well as first responders, in your thoughts."

Law enforcement officials speaking with reporters outside the two-year school located 180 miles south of Portland acknowledged that Umpqua Community College was a self-described "gun-free campus," with a policy in place informing its roughly 3,300 full-time students that firearms were forbidden on the campus. However, the AP notes that the grounds are currently protected by a single security guard who does not carry a gun, despite recent conversations within the school community about strengthening security before the fatal attack.

Shortly after Brown was sworn in as governor in February, making her the first openly LGBT governor in American history, she signed into law a stringent gun-control bill that requires universal background checks on all private gun sales.

At press time, it was unknown how, when, or where the gunman acquired his weapon, and whether he did so legally.