The British Home Secretary has targeted Facebook-owned WhatsApp's end-to-end encryption by saying that the feature offers terrorists a safe way to communicate before carrying attacks, the media reported.

Home Secretary Amber Rudd demanded on Sunday that the government agencies need to be able to peer inside the messaging app, tech news outlet ReCode reported on Sunday.

"We need to make sure that organisations like WhatsApp, and there are plenty of others like that, don't provide a secret place for terrorists to communicate with each other," the BBC quoted Rudd as saying.

"It used to be that people would steam open envelopes or just listen in on phones when they wanted to find out what people were doing, legally, through warranty."

"But on this situation we need to make sure that our intelligence services have the ability to get into situations like encrypted WhatsApp," she said.

According to a report published in the Telegraph, Rudd also said the country would also need assistance in combating terror from other technology giants, including Google, Twitter, and blogging platform WordPress.

Last year, US tech giant Apple denied decrypting the iPhone that the terrorist behind the 2015 San Bernardino attack used as the company "believed deeply that people in the US and around the world deserve data protection, security and privacy. Sacrificing one for the other only puts people and countries at greater risk."

Referring to the battle with the US government over encryption to unlock an iPhone, Apple CEO Tim Cook at that time reiterated the company's commitment to protect its users' data and privacy.

Rudd's critique echoed this fight between the US law enforcement and Apple and she said that Apple also had a responsibility to help government officials look into apps employed by its iPhone owners.

"If I was talking to (Apple CEO) Tim Cook, I would say to him that this is something completely different," she said.

"We're not saying 'open up', we don't want to 'go into the cloud'. we don't want to do all sorts of things like that," she added.

"But we do want them to recognise that they have a responsibility to engage with governments, and engage with law enforcement agencies when there is a terrorist situation. We would do it all through the carefully thought-through, legally covered arrangements. But they cannot get away with saying we are a different situation. They are not," she noted.

Meanwhile, a WhatsApp representative said, "We are horrified at the attack carried out in London earlier this week and are cooperating with law enforcement as they continue their investigations."

The 52-year-old lone attacker, Khalid Masood, used the Whatsapp messaging service just minutes before he smashed his hired car into the railings at the Houses of Parliament, The Independent daily claimed on Saturday.