Police have withdrawn from University of Tasmania campuses after an online threat against the university was discredited.

The anonymous social media post, threatening violence, was detected by university security on Monday night and police were called in to its Hobart, Launceston and Burnie campuses.

Police this afternoon ruled the threat was not credible, and posed no risk to staff and students.

Commander Glenn Frame told media in Hobart the post was likely to have come from the same person or group that issued a similar threat to the University of New South Wales on Monday.

"That's what we're looking at at this stage, and there is evidence to suggest that," he said.

"They're certainly not identical but there's enough similarities for us to consider that that's the most likely scenario.

"Social media is a fantastic thing for a lot of people, but it creates the opportunity for these sort of things to occur."

Safety risks being assessed

Commander Frame said although police were withdrawing from UTAS campuses, risk assessment would be ongoing, including monitoring of threats on social media.

He said the post had now been removed and Tasmanian police were working with their interstate counterparts to find the source.

"We believe the threat is consistent with other jurisdiction's threats, so we don't think it's a local incident," Commander Frame said.

Uniform officers were stationed at the entrances of the university campuses and officers patrolled university facilities, but Commander Frame said the measures were no longer needed.

"With a non-specific threat if you put resources somewhere without the intelligence to support it, it actually just decreases their ability to respond somewhere else," he said.

"Over the years we've responded to many many threats. The internet adds an added complexity to it but it's still our core business.

"We have got the capacity there and we're building it up and it's something we'll continually need to assess."

The university's Chris Smyth said the threat had been "very concerning."

But he said he was immensely relieved it had been discounted.

"I'm very grateful the threat has been assessed and there is no credibility to the threat," Mr Smyth said.

"But obviously we take these matters very seriously. The safety of our staff and students is paramount, so we deal with them very seriously."

Mr Smyth said the priority was reassuring the university community and reviewing the incident.

He said a security presence was expected to continue at the campuses.

Some students undeterred by threat

UTAS student union president Heidi La Paglia said she had advised students to stay home if they were concerned.

Police on patrol at UTAS in Hobart after staff and students were warned of a threat made on social media. ( ABC News: Edith Bevin )

"Because it is the last week of classes people often feel that that's the most important, because that's where they're going to get exam material.

"Given the email that was sent out I think most people would know that it would be OK not to attend because most classes are actually recorded as well."

Students and staff have turned up for lectures despite the threat.

Launceston UTAS student Lace Digney is preparing for her graduation show on Wednesday night.

The third-year student told ABC Northern Tasmania she would be on campus.

"I don't know how our director would feel if we all called up and said we don't feel comfortable coming in," she said.

"We have to be there, I know my mother ... will be messaging me to say do not go to school."

UTAS demographer Amina Keygan, who works at the Cradle Coast campus, said there were not many students around compared to usual.

"Given that it's the last week of classes before exams and that Tuesdays on campus here are normally the busiest days, there were about four or five students in the main communal working area so that's down significantly on numbers on a normal Tuesday," she said.