Gardai are investigating a suspected Islamic State terror cell based in the west of Ireland.
The "organised terror cell" is headed by two Chechen brothers who have been living in Ireland for a number of years.
Senior sources have revealed that gardai have been monitoring the activities of the eight-man cell for a number of months.
The suspected Islamic extremists, who live in various rural locations, are being investigated for using An Post and courier services for 'dummy runs' to send items to the war-torn Middle East.
The jihadi group is also suspected of being involved in fundraising and electronically transferring funds from Ireland to extremist Islamic organisations.
"The belief is that members of this network are deeply committed to the Islamic State and they are organised," a source said.
"It has been established that they have attempted to send small internal parts of computers to locations such as Chechnya, Iraq and Syria.
"It is believed that they have been doing this as 'dummy runs' for perhaps attempting to send something more sinister such as bomb components out of the country."
The group is being monitored by detectives based in Galway but the Special Detective Unit's Counter-Terrorism International (CTI) Unit is also aware of the suspected terror cell's activities and it is understood that international authorities are as well.
While the group's members, including the two brothers who are suspected of leading it, have been questioned by gardai in the past, they have not yet been arrested for any terrorist offences.
"Of course there is major concern about this radicalised extremist group and that is why they are being closely monitored," the source added.
It is understood that there are around eight men linked to the suspected cell, all of whom live in the west. Their photographs have been circulated among gardai in the surrounding areas in order to keep tabs on them.
The revelation comes after the Herald revealed earlier this week that Islamist extremists are using unsuspecting students at Irish third level colleges to transfer the proceeds of internet fraud to finance Islamic State terrorist operations.
The unwitting, mostly foreign students are duped into opening personal accounts in Irish banks by secret IS sympathisers who are members of a back-up network providing logistical support in the form of cash and false travel documents to terrorists in Britain and Europe.
Known in the security world as "mules", the oblivious participants are given money to open the accounts in return for the Pin codes, ATM cards and online banking details.
Gardai remain deeply concerned that an Islamic terror attack could happen here and are constantly preparing for such an eventuality, but the threat level still officially remains moderate.
This means that an attack is possible but not likely.
Last month, it emerged that a 'shoot first' policy against jihadi-style terrorists would be adopted by gardai under a new anti-terror plan.
The new rules, which have been circulated to all senior officers in Dublin, will reverse the force's previously cautious approach to using firearms, even in terrorist situations.
Instead, officers will be encouraged to shoot suspects dead if, for example, they believe a jihadi attack is unfolding.
The new proposals are also expected to require significant extra training for armed officers and the reallocation of resources to ensure armed gardai can get to an attack scene quickly.
There are increasing fears that Ireland is being used as a hub by jihadists and that gardai are ill-equipped to deal with the issue after a spate of attacks in England as well as continental Europe.
In an interview with the Herald after it emerged that London terror attacker Rachid Redouane (30) had lived in Dublin, a senior investigator warned that gardai needed to use highly trained and experienced officers to deal with the Muslim community to combat the growing problem of Islamic extremism in this country.
The investigator said the force "should be proactive" in dealing with the threat from Islamic extremists in Ireland.
"Ireland is now in the best position to deal with this issue," said the investigator, who has experience of fighting international terror groups.
"We have a reasonably small Muslim community that is semi-integrated with local communities here.
"Ireland does not have ghettos like what exist in the UK, France and Belgium and the opportunity is here to ensure that people in the Muslim community do not get marginalised.
"There are difficulties here but to stop the problem getting worse we need experienced gardai to deal with these communities.
"There are a lot of people in the gardai who have the natural ability to communicate and these are the people who need to be utilised now.
"When dealing with this community, officers need to know the background of who they are dealing with, where they are from, what strand of the Islamic faith they are, their allegiances, their ideologies and most importantly to discover whether there are individuals who have a mindset towards violence."