Counter-terror forces have revealed that a terrorist attack in Australia is 'probable' but are encouraging residents to go about their business as usual.

It comes after it was reported the country is on high alert with fears Islamic State is set to launch a series of attacks around the world on Wednesday, a key date of Ramadan.

'Night of Power', which falls on the 27th day of Ramadan, has been a notorious target for ISIS terrorists, who slaughtered 20 people in a Bangladesh restaurant last year.

And now, in the wake of last month's Manchester attack, the London Bridge attack and Monday's incident at a London mosque, there are fears ISIS could be set to again ramp up attacks, forcing Australian authorities to be extra vigilant, Nine News reports.

Counter-terror forces have revealed that a terrorist attack in Australia is 'probable' but are encouraging residents to go about their business as usual (pictured is the Manchester attack)

It comes after it was reported the country is on high alert with fears Islamic State is set to launch a series of attacks around the world on Wednesday, a key date of Ramadan (pictured is Monday's incident at a London Mosque)

Counter-terror forces in Australia (pictured) are on high alert with fears Islamic State is set to launch a series of attacks around the world on Wednesday, a key date during Ramadan

A major date on the Ramadan calendar, 'Night of Power' or Laylat al-Qadr, is the day when Muslims believe Mohammed first revealed the verses of the Quran.

Last year's attack at Dhaka, in Bangladesh, saw nine Italians, seven Japanese, two Indians and an American killed when ISIS soldiers burst into the eatery with knives.

Authorities in Australia are expected to be out in force and on the lookout for suspicious activity.

NSW Police told Daily Mail Australia 'there is not state of high alert and members of the community are encouraged to go about their daily activities as they normally would.'

'The National Terrorism Threat Level remains at "probable" and there is no intelligence of any specific threat at this time.'

It comes after messages from pro-ISIS supporters warning extremists would wage a 'war' on streets were revealed in the wake of London's latest suspected terror attack.

'When your brothers took revenge on the Crusader nationals for the slaughter they are carrying out on the Muslims they were shot on site (sic) by the British Police,' the messages read.

'Then how come the police never shot a Kafir (non-Muslim believer).

'Night of Power', which falls on the 27th day of Ramadan, has been a notorious target for ISIS terrorists (pictured), who slaughtered 20 foreigners in a Bangladesh restaurant last year

in the wake of last month's Manchester attack and Monday's incident near a London mosque (pictured), there are fears ISIS could be set to again ramp up attacks, forcing Australian authorities to be extra vigilant

It comes after messages (pictured) from pro-ISIS supporters warning extremists would wage a 'war' on streets were revealed in the wake of London's latest suspected terror attack

Darren Osborne (pictured) was arrested in relation to the attack outside the mosque

'You need to wake up the war is starting now in your own streets outside your own Masajids (mosques).

'Your elders could be killed, your sisters could be attacked.'

Father-of-four Darren Osborne, 47, was arrested on suspicion of murder and terror charges in relation to the attack outside the mosque on Monday morning.

One man was killed while a further 10 people were treated for injuries after a hired white van hit a group of people.

Some claim he shouted 'I'm going to kill all Muslims - I did my bit' and other 'this is for London Bridge', after ramming a van into a crowd of Muslims.