After the deadly shootings and suicide bombings in public places in France, a British official recently warned that the Islamic State (ISIS) jihadist organisation could be plotting another attack, this time targeting Britain.

British Chancellor of the Exchequer George Osborne said the attack could be a different kind—cyber attack.

Osborne said the terrorist group is out to hack vital U.K. infrastructure such as hospitals and air traffic control systems, in a bid to harm the nation's economy and ultimately to kill people.

"The stakes could hardly be higher. If our electricity supply, or our air traffic control, or our hospitals were successfully attacked online, the impact could be measured not just in terms of economic damage but of lives lost," Osborne was quoted by BBC as saying.

"From our banks to our cars, our military to our schools, whatever is online is also a target," he added.

While saying that the ISIS militants "do not yet have that capability" to launch a cyberattack on Britain now, Osborne encouraged the government and the public to observe "basic rules of keeping themselves safe" online.

The British official said the Government Communications Headquarters (GCHQ), Britain's intelligence agency, is currently monitoring 450 vital companies from the fields of energy, defence and water supply, to protect them against potential cyberattacks.

He also revealed that British spies are developing capabilities to be able to counter the ISIS' plot to hack vital U.K. cyber infrastructure.

"We will defend ourselves. But we will also take the fight to you," Osborne said.

"Strong defences are necessary for our long-term security. But the capacity to attack is also a form of defence," he added.

The British finance official further said that his government will invest nearly 2 billion pounds to support the creation of a cyber force that will combat online threats from terror groups.