Security minister Baroness Pauline Neville-Jones has warned that the risk to the UK of cyber terrorism is growing, and that terrorists are developing "serious cyber-attack capabilities".
The Telegraph reported that the minister, speaking at a conference on online jihadism, said: "In some form, a cyber-attack attempted by terrorists, if not inevitable, is of so great a likelihood that we bear it in mind in developing operational capabilities."
She added that the internet is as useful a tool for terrorists as it is for businesses, consumers and law enforcement.
Security firms and law enforcement agencies keep track of dozens of terrorist sites involved with recruitment, logistics and publicity, but they are almost impossible to take down as they could be hosted anywhere in the world, and rarely remain on the same server for long durations.
It is thought that critical infrastructure such as power stations or telecommunications networks could be the next target for cyber terrorists.
Patrick Ciganer, director of the US Department of Energy's transparency initiative, said: "We had a simple point-to-point system with a clearly defined set up of controls, but as [the system] gets smarter with localised intelligence the risk will increase. With multi-layered interconnectivity you are opening the door to a broader set of vulnerabilities."