IT IS too early for a definitive analysis of the Manchester suicide bombing but the nature of the attack and the device used provides significant indicators as to who might be behind it.

To begin with, this was a bomb – not the knives and vehicles used to stab and mow down victims as in other UK attacks, such as the one in Westminster in March.

Most security experts agree that to be able to assemble such a device safely and to detonate it in such a prominent location at a key time suggests a more organised effort.

For that reason a so-called “lone wolf” attacker has been pretty much ruled out in the Manchester concert bombing.

At the very least, the bomber would most likely have had help either in person or electronically through messaging apps or online forums.

There are simple bombs and there are sophisticated bombs but, as explosive ordnance disposal (EOD) experts will attest, it does always need a certain level of technical ability that requires a degree of training, some practice or some sort of technical skills.

Some kind of reconnaissance was also probably undertaken before the Manchester attack.

The first thing investigators will be looking to establish is the nature of the bomb residue.

Terror groups tend to have what is known as an “explosive signature”.

On the face of it, the Manchester bomb bears a strong similarity to that used by seven of the eight attackers in the Paris atrocities of November 2015.

The terrorists then detonated shrapnel-packed bomb vests designed for causing the maximum number of casualties while committing suicide. The key ingredient in these bombs was a compound called triacetate triperoxide, or TATP, a crystalline powder that is easy to make and hard to detect but also incredibly unstable. In fact, all it takes is a firm blow to explode TATP with a force that is about 80 per cent as strong as TNT.

And the higher the volume of TATP, the more volatile it becomes. Jihadist terrorists who make it have dubbed it “the mother of Satan”.

One reason TATP is difficult to detect is because it is peroxide based and does not contain nitrogen, a key component of homemade “fertiliser” bombs, which security scanners are very good at finding.

This is why there has been so much concern lately over passengers taking laptops aboard aircraft because TATP can easily be placed inside such devices.

Since 2014, the Islamic State has used TATP in Europe.

IS has claimed responsibility and the Manchester attack fits with past targeting patterns of the terrorist group.

Concert venues and clubs targeted previously include the IS attack on the Bataclan concert hall in Paris in November 2015, which killed 89 people and the attack on the Pulse nightclub in Orlando, Florida, in June last year, which killed 49 people.

It should be stressed, however, that al Qaida have also used such devices and there has been much speculation that the group, which has been overshadowed of late by IS, has been making a comeback and has always shown a capacity for more elaborate strikes.

As ever, IS-linked websites showed lots of activity in the wake of the Manchester attack, but this is to be expected.

IS central media, on the other hand, according to security experts, were effectively dormant from 9.30pm on Monday. These factors are significant because it important to remember there is a difference between official IS channels and unofficial ones.

It is on official channels that claims are posted.

Beyond these there are hundreds of unofficial pro-IS channels and forums.

IS often waits for some time after attacks in the West before making a statement, partly to ensure it does not claim credit for an attack that was carried out by al Qaida or another group.

For now it appears the Manchester suicide bomber, who demonstrated a deadly competence most likely was part of a terror cell already known to MI5.

GCHQ will now be looking for a digital trail and, if necessary, MI6 will speak to foreign partners to build a picture of who this man was and who he knew.

They will check whether the bomber might have been remotely “directed” by a centralised body, for example IS leadership in the Syrian city of Raqqa, or whether it was indeed orchestrated closer to home.

Already one man has been arrested in Manchester in connection with the attack, which would suggest the security services have some solid leads to follow.