LATEST INFORMATION: SOUTHERN Cross University's Lismore campus opened as normal on Wednesday after "enduring an emergency lasting several hours" on Tuesday.

Vice Chancellor Adam Shoemaker confirmed there were no injuries to anyone on campus.

"I want to thank the NSW Police Force, all members of campus security, our Chaplaincy colleagues, and-especially-all staff and students who were caught up in the events," he said.

"The level of cooperation with the essential lock-down procedures was just outstanding.

"There is no doubt it has been a stressful and for some, disturbing ordeal.

"Counselling will be available through the critical incident debriefing service, our own counselling service and the employee assistance program today and for the coming weeks."

NSW Police said the operation was launched after a threatening phone call was received by police from the Richmond Police District around 1.30pm on Tuesday.

Police evacuated about 800 people and locked down the campus. Nearby schools also initiated lockdowns.

"There were no reports of shots fired and following an extensive search of the campus, no credible threat was detected," police said.

"One female student was conveyed to Lismore Base Hospital for a minor injury not related to the threatening phone call."

An investigation is now under way into the source of the phone call.

Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au. Information is treated in strict confidence.

Southern Cross University's Lismore campus is in lockdown. Marc Stapelberg

UPDATE, Tuesday 5.45pm: FEARS an active shooter was at Lismore's Southern Cross University campus have been shut down after a four-hour police lockdown.

Police lifted the lockdown just before 5pm and are investigating whether it was an "elaborate hoax" or there was some substance to the threats.

NSW Police Acting Commissioner Wayne Humphrey said the area was safe and there were no guns found on the campus.

He also said the emergency response was triggered by a phone call was received at Casino Police Station.

UPDATE, 5.15pm: SOUTHERN Cross University's Vice Chancellor Professor Adam Shoemaker confirmed a building-by-building procedure was under way to ensure a safe and controlled exit of all staff and students.

"The university has organised buses to take people to Lismore CBD, Goonellabah and surrounding areas," he said.

"Before leaving the campus, people will be checked by police as a precaution.

"The campus is still under police control and we will let people know of further updates as soon as possible via email and our Southern Cross University Facebook page.

"This has been a stressful few hours and I want to thank everyone for their amazing patience and co-operation.

"I urge everyone to continue to follow police direction."

UPDATE 5pm: SOUTHERN Cross University say police have instructed the Lismore campus to be evacuated.

"Vice Chancellor Professor Adam Shoemaker said a building-by-building procedure was under way to ensure a safe and controlled exit of all staff and students," SCUonline posted on Twitter.

UPDATE, 4.50pm: AFTER a three-hour lockdown at Southern Cross University, police have said the situation is now safe.

At a police press conference in Sydney this afternoon, officers advised that the situation at the Lismore campus was safe for students and staff members.

Police confirmed that no-one was found with a gun.

At this stage it is unclear whether those who were in the library at the time of the lockdown are being allowed to leave the campus.

More to come.

UPDATE 4.19pm: SOUTHERN Cross University has advised their Lismore campus is still in lock-down.

"Students and staff are advised to remain inside," they wrote on social media.

"We will provide further updates as soon as possible."

UPDATE, 3.50pm: POLICE will this afternoon provide an update to the media in relation to the police operation currently under way at Southern Cross University at Lismore.

About 1.30pm today, a number of threatening phone calls were received, police said.

As a result, the university and a nearby high school were locked down.

There have been no reports of injury or shots fired.

A police operation remains ongoing, involving officers from Richmond Police District and other specialist resources.

Police are advising the public to avoid the area as the operation continues.

UPDATE, 3.25pm: POLICE have confirmed that Lismore's Southern Cross University and Lismore High school have been locked down, after threatening phone calls were received about 1.30pm today.

There have been no reports of injury or shots fired.

A police operation is underway involving officers from Richmond Police District and other specialist resources.

Police are advising the public to avoid the area as the operation continues.

No further information is available at this time.

UPDATE, 3.05pm: A WOMAN who is at the university's plaza is watching the lockdown situation unfold.

Louise Hardman, posting on The Northern Star's Facebook page, said she saw "five policemen with machine guns just came in moving towards the library region, pointing their guns and using hand signals".

She described the situation as "freaky".

UPDATE, 2.45pm: AN SCU student who is locked on the second floor of the library has confirmed he's heard reports there's at least one shooter on campus.

Rhys Harrison said he was currently in lockdown with about 60 people.

"The stress level seems pretty high but no one is panicking," he said.

Meanwhile, students from Wyrallah Road Public School have been advised that they are safe to travel home on buses.

Any student who walk or ride a bike home will be held at school and parents are asked to collect their child/ren from the school.

Southern Cross University's Lismore campus is in lockdown. Marc Stapelberg

UPDATE, 2.20pm: SOUTHERN Cross University is urging all students and staff members to stay inside, with the Lismore campus currently in emergency lockdown.

One student, Angus Field, posted on Instagram: "Holy f--k there's a shooter at uni".

There have been other reports of two gunmen on the campus.

Sirens have been heard coming from the university this afternoon as police surround the facility.

The reports of an armed person on campus have not been confirmed by authorities, but police continue to converge on the uni.

Police are urging people to keep well away from the area.

Lismore High and the nearby childcare centre, Blinkys, are also in lockdown.

Parents have been assured that all children are safe and indoors.

SCU student in lockdown: SOUTHERN Cross University is urging all students and staff members to stay inside, with the Lismore campus currently in emergency lockdown.

UPDATE, 2.15pm: A POLICE operation is currently underway at Southern Cross University campus, Lismore.

Officers from Richmond Police District and specialist resources are on the scene.

Police are advising the public to avoid the area.

No further information is available at this time.

The Rivers Secondary College Lismore High campus is also in lockdown this afternoon.

"The school is currently in lockdown due to an unfolding matter at the university," the principal posted on the school's Facebook page.

"Students are safe and the school will remain in lockdown until advised by police.

"Please do not attempt to collect your child. We will update you when possible."

NSW Education spokesman has confirmed the school has been placed into lockdown as a result of the incident on SCU campus.

"As a precaution the police advised the school in lockdown," he said.

"The school has let parents know.

"The incident is not related to the school."

The university has urged anyone on campus to "stay indoors".

Original story: POLICE and emergency services are rushing to Southern Cross University's Lismore campus this afternoon, where a serious situation is unfolding.

Police could not confirm details at this stage, but people are being urged to stay away from the area.

It is understood the university is currently in lockdown.

Police are patrolling the entrance to the facility and turning away all students and staff members, saying it will be a long time before the uni reopens.

The SCU law students posted on their Facebook page: "Please be aware that the Campus is in emergency lockdown. Please follow all warning announcements and stay indoors. You'll be advised on further instructions by staff on campus."

Ambulance crews have been called to Southern Cross University Lismore Campus, following a police lockdown.

An Ambulance NSW spokeswoman confirmed one crew was on scene.

"We're not treating anyone, we're there on operational standby only," she said.

More to come.