THE threat of terrorism should not stop Australians taking part in Anzac Centenary events in greater numbers than ever before, Prime Minister Tony Abbott said.

The announcement came after five men were taken into custody this morning during dramatic raids across Melbourne after police learned of an alleged plot, possibly against police officers, at Anzac events in the Victorian capital.

Police this afternoon charged 18-year-old Hallam teenager Sevdet Besim with “conspiracy to commit acts done in preparation for, or planning, terrorist acts”, a Commonwealth offence, Herald Sun reports.

Mr Besim appeared for a 30-second hearing at the Melbourne Magistrates’ Court where he was remanded in custody to reappear for a filing hearing on April 24.

An 18-year-old Hampton Park man was also arrested in relation to terrorism-related offences.

There would be a greater police presence throughout Victoria and around Australia as authorities upped the ante against those plotting terrorist attacks, authorities said.

At a joint media conference with Australian Federal Police Deputy Police Commissioner Michael Phelan this afternoon, Mr Abbott said everything “humanly possible” was being done to keep people safe.

Going to Anzac services in “big numbers” was “the best thing people could do in the face of those who would do us harm,” Mr Abbott said.

Mr Phelan said the terror threat “was real”.

At a press conference this morning, police revealed the arrested men were “associates” of the dead Melbourne terrorist Numan Haider, who was shot by police last year.

The group were being closely watched by police but Mr Phelan said police “ramped up” efforts when new information came to light.

Mr Abbott said the alleged Melbourne plot was the only one security agencies were aware of that they believed was in an advanced stage.

Melbourne has long been a mecca for Anzac Day celebrations across Australia. Last year record numbers of around 80,000 people turned out for dawn services with tens of thousands following for later parades. Those numbers were set to explode this year with the centenary of the Anzacs.

And at the MCG the popular Anzac Day AFL clash between Collingwood and Essendon has capacity for around 100,000 spectators.

Mr Andrews said he would join senior police at the Anzac memorials next week and urged residents to go about their business as usual and not let the threats change them.

“That’s not the Victorian way, it’s not the Australian way.”

A number of knives and swords were discovered by police during the raids which began at 3.30am.

Mr Andrews sai the alleged plot was “a shocking” situation that appeared to be “ISIS inspired”.

“It’s a reminder to all of us that these threats of violent extremism, radicalisation, that confronts us all [and] challenges us.”

He warned the true extent of the threat was probably still unknown because authorities “don’t really understand” the mentality of the individuals.

“They are not men of faith, it doesn’t matter where you pray or where you are born. It’s not an issue of how you pray.”

While the public had a right to feel frightened and scared, Mr Andrews was confident the raids and arrests were a sign “the system” worked.

Earlier this morning, at a joint Victoria Police and Australian Federal Police press conference police said they believed the group were not working in conjunction with other organisations.

“The persons involved in this are individuals acting by themselves,” and were not representative of any religion, group or culture officers said.

Victoria Police acting Deputy Commissioner Shane Patton said the alleged attacks could have occurred any day.

“We believe the attack could have occurred at any time within the next week,” he claimed.

A major concern of the police was the young age of the men involved.

“We need to have intervention strategies to make sure they don’t do down this path,” He said

“People should not feel anxious by this, the community should feel comfortable that we’re out there doing our job,” DC Patton said.

In a statement this morning, Victoria Police said it, along with the AFP, executed a number of warrants following a major Melbourne Joint Counter Terrorism Team operation.

Investigators allege two of the men were planning an attack in Australia targeting police officers.

“Operation Rising has resulted in the execution of seven search warrants in the South Eastern Metropolitan area and the arrest of five men.

“An 18-year-old Hallam man and an 18-year-old Hampton Park man have been arrested regarding terrorism-related offences,” the statement said.

“It is alleged the men were undertaking preparations for planning a terrorist act in Australia, which included targeting police officers.

A third man, an 18-year-old from Narre Warren was arrested over weapons offences.

Neighbours told the Herald Sun of how they were woken by screams in the early morning.

“I’m quite a heavy sleeper but got woken up by a metallic banging kind of sound and just a whole flurry of screaming for about 30 seconds and then it deadened down,” said one neighbour.

Investigations are ongoing.