Children as young as nine have been left “petrified” that Britain could be hit by an Isis terror attack, a leading charity has warned.

Youngsters contacting the NSPCC's Childline service have suffered panic attacks, anxiety and insomnia triggered or exacerbated by atrocities around the world.

In the last year, the facility has handled 660 counselling sessions about terrorism, with children discussing conflicts in the Middle East and often mentioning Isis.

Sting brings music back to the Bataclan one year after Paris atrocity

It is the first year the service has specifically recorded contacts concerning terrorism after a surge in the wake of the Paris attacks. Extremists killed 130 people in mass shootings and bomb attacks in the French capital a year ago. Subsequent atrocities in Brussels, Orlando and Nice all triggered a higher volume of calls to Childline.

Where the age was known, a fifth of contacts about terrorism were from children aged 11 and under, while girls were twice as likely as boys to seek support from the service.

Many youngsters feared the outbreak of war and frequently reported that they were afraid of a terror attack hurting their families.

One 11-year-old boy said: “I'm so scared at the moment with everything going on. I constantly feel anxious about terrorism and think that Isis is going to attack the UK soon. I am really worried that they will get someone in my family. I haven't been sleeping because it is all I can think about.”

A 14-year-old girl, said: “My anxiety is becoming worse after the terrorist attacks. I'm really worried something like this could happen in London.”

Terrorism in 2016: Terror attacks in Europe claimed by Isis Show all 9 1 /9 Terrorism in 2016: Terror attacks in Europe claimed by Isis Terrorism in 2016: Terror attacks in Europe claimed by Isis Policemen outside Rouen's cathedral during the funeral of Jacques Hamel, the priest who was killed in a church in Saint-Etienne-du-Rouvray in Normandy on 26 July during a hostage-taking claimed by Islamic State group Joel Saget/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis Two jihadists, both 19, slit Hamel's throat while he was celebrating mass in an attack that shocked France as well as the Catholic Church Joel Saget/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis Muslims place flowers and hold a minute of silence in front of the church if Saint-Etienne-du-Rouvray, western France, where French priest Jacques Hamel was killed on 26 July Charly Triballeau/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis Two people hold each other by the new makeshift memorial in Nice, in tribute to the victims of the deadly Bastille Day attack at the Promenade des Anglais Valery Hache/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis The Islamic State group claimed responsibility for the truck attack that killed 84 people in Nice on France's national holiday. Mohamed Lahouaiej-Bouhlel, 31, smashed a 19-tonne truck into a packed crowd of people in the Riviera city celebrating Bastille Day Valery Hache/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis Police work at a site where a Syrian migrant set off an explosive device in Ansbach, southern Germany, on 25 July, killing himself and wounding a dozen others Daniel Roland/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis A Syrian migrant set off an explosion at a bar in southern Germany that killed himself and wounded a dozen others in the third attack to hit Bavaria in a week. The 27-year-old, who had spent a stint in a psychiatric facility, had intended to target a music festival in the city of Ansbach but was turned away because he did not have a ticket Friebe/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis Police officers walk along train tracks in Wuerzburg southern Germany on 19 July, a day after a man attacked train passengers with an axe. German authorities said they had found a hand-painted IS flag among the belongings of the man, an asylum seeker from Afghanistan, who seriously injured four members of a family of tourists from Hong Kong in his rampage Daniel Roland/AFP/Getty Images Terrorism in 2016: Terror attacks in Europe claimed by Isis German police killed a teenage assailant after he attacked passengers on a train in Wuerzburg, southerg Germany with an axe and a knife on 18 July, seriously wounding three people Karl-Josef Hildenbrand/AFP/Getty Images

Attacks overseas in recent months have heightened fears Britain could be targeted. The official threat level for international terrorism in the UK is “severe”, meaning an attack is “highly likely”.

NSPCC chief executive Peter Wanless said: “These vicious attacks have seared themselves into the consciousness of children, who tell us how petrified they are of these sadistic atrocities happening on UK shores.

“The past 12 months have been stained by these bloody events and it is little wonder that young people are so frightened about terrorism. Sadly we now live in a world where the months are punctuated by these inhumane attacks, so it is vital that we do not brush young people's fears aside.

“Instead, we must listen to their worries and reassure them that there are people doing everything they can to keep us all safe.

“Childline is always hear to listen to a child, and our helpline can offer adults advice on how to comfort and talk to children about difficult topics.”

Any young person who is worried can call Childline free and anonymously on 0800 11 11, and adults who want advice on how to talk to their child about terrorism can call the NSPCC Helpline on 0808 800 5000.