A manhunt was underway for a gunman who shot and killed two people at a university in the US state of Michigan.
Central Michigan University said the two people killed at a campus dormitory were not students or staff, but did not offer further details on their identities.
There were no other casualties.
A university police spokesman said the incident as a "family-type domestic issue" and identified the suspected shooter as 19-year-old James Eric Davis, described as a university student.
The college campus in the city of Mount Pleasant in central Michigan was on lockdown hours after the incident, as an expansive manhunt searched for the suspect.
Davis was known to law enforcement. Police took him to a hospital the night before for what was believed to be a "drug-related type of incident -- an overdose or a bad reaction to drugs," campus police spokesman Larry Klaus told a news conference.
He was then released to hospital staff, Klaus said.
He said anyone who sees Davis shouldn't confront him, but needs to call 911. The school, which has about 23,000 students, urged everyone on campus to take shelter.
"He should be considered armed and dangerous," said Klaus, adding that Davis was wearing a black hoodie but had been shedding certain clothes while on the run.
The shooting comes amid a renewed debate over pervasive gun violence and law enforcement's role in stopping potential shooters, which was sparked when a teenage gunman killed 17 people at a Florida high school two weeks ago.
The gunman in that shooting had a history of run-ins with law enforcement, which have faced scrutiny over their failure to intervene despite multiple warnings.
It was unclear what kind of weapon the shooter in Michigan used or how he acquired it.
The state of Michigan allows for the concealed carrying of a handgun with a permit, but Central Michigan University does not allow guns on campus.
The reaction to the shooting was swift Friday morning, with multiple alerts going out on social media and mobile phones within minutes of the incident at 8:30 am (1330 GMT), cautioning students and staff to shelter in place.
They remained locked down in classrooms and dormitories hours later. Classes were canceled and visitors urged to stay away from campus.
With one day left before residence halls were scheduled to close for spring break, parents seeking out their children were told to go to a staging area at a nearby hotel.
"The university is taking all precautions. The number one priority right now is safety," said university spokeswoman Sherry Knight.
In response to the shooting in Parkland, Florida, in which gunman Nikolas Cruz used a semi-automatic assault rifle, students at Marjory Stoneman Douglas High School have made public appeals for change to permissive US gun laws.
President Donald Trump has called for training and arming some teachers, tougher background checks and a potential increase to the minimum age for rifle purchases.
But the powerful National Rifle Association gun lobby said that Trump was opposed to gun control after meeting with him on Thursday.
