STUDENTS and staff from Southern Cross University's Lismore campus are still in shock after yesterday's lockdown ordeal, which lasted four terrifying hours.

The lockdown started around 1.30pm and saw 800 people ordered to stay within the library grounds.

Many of those people were in the library, which was the area of main concern for police.

It was the library building which specialist police stormed, methodically scanning the building with their guns pointed, looking for any signs of danger.

Meanwhile, terrified students and staff wondered what was happening.

One woman shared a video of the armed officers going up the library stairs, with the caption, "this is reassuring".

Alarms sounded throughout the university's campus, with the warning: "Attention, attention, the campus is under emergency lockdown".

Other than that, the usually bustling library was eerily quiet.

In another video from the scene, a woman was heard to say: "I just can't... this is not ideal".

The video showed a heavily armed and camouflaged officer patrolling the university grounds, and she had captioned it: "Love a few school shooters in Australia". 

Staff and students were eventually allowed to leave the campus, with many shocked to see how many police resources had been called in to deal with the situation. 

Local police attended the campus, where they were assisted by specialist units; including Tactical Operations Regional Support (TORS), the Negotiation Unit, the Rescue & Bomb Disposal Unit, and Traffic and Highway Patrol Command.

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