THERE is little we can do to prevent attacks by Jihadis at major public events, a terrorism expert has warned.

Andy Oppenheimer, a counter terrorism analyst, said we should expect more bloodshed with Islamic extremism unlikely to be defeated for decades.

Sussex hosts hundreds of major public events each year, with the likes of Brighton Pride, Brighton Festival and the marathon alone attracting tens of thousands.

However, Mr Oppenheimer said there is little we can do to stop attacks such as the one at Manchester Arena. He said: “Unless we live in a police state there is little we can do. We are widely watched with thousands of CCTV cameras but it is impossible to watch everyone all of the time.

“During the Troubles people used to get searched in Belfast if they went down to the shops. There were soldiers everywhere. They just got used to it. It was like that for 30 years but we can’t go back to that.

“With regards to public events, you can’t search everybody, it just isn’t possible. The fact is that if it wasn’t for the fantastic work done by our intelligence services there would have been many more incidents like this.”

Unlike recent attacks, in which knives, guns and vehicles have been used as weapons, the Manchester attacker appears to have used a homemade bomb.

He said: “This is a definite step up from what we have seen recently. The bomb is still the terrorist’s weapon of choice as it inflicts the most amount of damage.

“People plotting to kill like this are inventive. They are only limited by their imaginations. They can make these bombs from materials that are readily available, be it scientific or domestic products. These items are also available on the internet which makes it difficult to track.

“But to make such a weapon there has to be a certain level of expertise and a supply chain which suggests others were involved in this plot.”

Mr Oppenheimer also warned against any quick fix and said Brighton was a legitimate target. He said: “Any city which attracts large numbers of tourists is a target so yes, I do worry for Brighton. This is not going to go away any time soon. Their views are deep rooted and they see this is a long-term battle.

“We lived with the IRA and got to the stage where we expected bombings and attacks. It almost became the norm. The only difference here is the agenda and the scale.

“With the IRA, it was based in a very small part of Europe. This is worldwide.

“We may be able to drive IS out of Syria and Iraq but there will still be attacks.

“You can’t just put a sticking plaster on this. We have got a long way to go, this is likely to go on for decades.”

He said the murder of so many young people would be viewed by IS supporters as a great victory. He said: “It is difficult for us to get our heads round and understand but for them it is like winning the Battle of Waterloo. We shouldn’t be surprised by them targeting young people. We shouldn’t be surprised by anything. Nothing is off limits. In the Middle East they have attacked churches, mosques and even other Muslims.”

He said there were no easy way to prevent attacks but said we can play our part by being vigilant and looking out for unattended bags and people acting suspiciously.

As for event organisers, he said they faced a difficult task. He added: “I go to security conferences and just for them you have to queue outside and wait to go through airport style security. But you can’t search everyone with events like this.

“If you do then you have a huge queue outside and then that becomes a target.

“Look at what happens in Iraq. You have all these men queueing up to become police officers and a bomber walks up and detonates himself.”

Sussex Police said yesterday that while there was no immediate threat in the county, security will be increased for big public events this summer, including the Little Mix concert at the South of England Showground on September 1.

World leaders, military generals and academics have long sought to discover how to destroy IS. Mr Oppenheimer said it would not be an easy task. He said: “You can’t destroy them by driving them out of Iraq and Syria, this is worldwide problem.

“The hope is that this is something which will eventually just burn itself out. Hopefully followers will eventually decide that it isn’t the way and they will get disgruntled. But I can’t see it happening any time soon.”