One person has been shot dead and three others have been injured when a gunman opened fire at a university campus in Seattle in the US.
Police were called to Seattle Pacific University at 3.30pm on Thursday, local time, to reports that a gunman had walked into the university's Otto Miller Hall and began shooting students.
Captain Chris Fowler, from the Seattle Police Department, said the gunman was armed with a shotgun and opened fire on three students in the building's foyer.
"At that point the shooter began to reload and a student that is the building monitor inside of the hall confronted the shooter. He was able to subdue the individual before other students jumped on top," he said.
The students pinned down the gunman until police arrived a short time later, Captain Fowler said.
Seattle police placed the campus on lockdown, with students told to get on the ground and stay away from windows.
There was initial confusion, with reports there were two gunmen involved in the shooting, which occurred on the second last day of the university year. However police later confirmed that they had a lone suspect in custody.
The victims were taken to Harborview Medical Centre for treatment.
A hospital spokeswoman said one man, aged in his 20s, had died.
A 20-year-old woman was in surgery with critical injuries, while a 24-year-old man and a 22-year-old man were in a satisfactory condition, she said.
A student, Jordan Heff, told the Seattle Times that he initially thought the gunshots were a science experiment.
“I was in physics and people heard a loud bang – we thought it was a science experiment," he said.
"We heard crying and yelling outside our door. We walked out and there were blood stains all over the carpet."
Another person from a nearby business told Seattle television station KIRO-TV that a gunman walked into the university hall and did not speak as he opened fire on students.
About 4000 students attend the Christian university, which is located about 10 minutes from downtown Seattle.
Seattle Mayor Ed Murray said an "epidemic of gun violence is haunting this nation".
"Today should have been a day of celebration at the end of the school year. Instead it's a day of tragedy and of loss," he said.
"This is a tragic moment for Seattle and a tragic moment for America, once again."