YEREVAN, AUGUST 25, ARMENPRESS. Facabook Inc., Alphabet Inc.’s Google and Twitter Inc. are deliberately shirking responsibility in the fight against Islamic State and other terrorist groups, an influential committee of British lawmakers said in a report to be published Thursday, reigniting a war of words over the role social media plays in radicalization, the Wall Street Journal reported.

“Huge corporations like Google, Facebook and Twitter, with their billion-dollar incomes, are consciously failing to tackle this threat and passing the buck by hiding behind their supranational legal status, despite knowing that their sites are being used by the instigators of terror,” said lawmaker Keith Vaz, a member of the opposition Labour Party, who heads the committee.

A wave of terrorist attacks in Europe and the U.S. has hardened the long-running debate between technology companies, who want to protect free speech and the privacy of their customers, and governments, who say they need more access to information to thwart plots. On Tuesday, France and Germany urged the European Union to propose rules that would compel operators of internet-messaging services to help authorities decrypt private communications on popular platforms, such as Facebook’s WhatsApp and Apple Inc.’s iMessage.

The report by the U.K. Parliament’s Home Affairs Committee, a cross-party panel of lawmakers that oversees the Interior Ministry, is the latest British broadside fired at Silicon Valley. Last year, the country’s top counterterrorism cop accused recalcitrant social-media firms of scuttling investigations by alerting suspects that detectives were after their communications data.

The three companies, in representations to the committee earlier this year, denied they are lax and said they cooperate with law enforcement to remove extremist content. Last week, Twitter said it had suspended 360,000 terrorist-related accounts since the middle of 2015. A spokesman declined additional comment.

Google’s YouTube said it encourages users to flag content and other users who promote terrorism so it can remove them. Google removed more than 14 million videos in 2014, according to the panel’s report. “We take our role in combating the spread of extremist material very seriously,” YouTube said in a statement.

Simon Milner, Facebook U.K.’s director of policy, said in a statement that “terrorists and the support of terrorist activity are not allowed on Facebook and we deal swiftly and robustly with reports of terrorism-related content.”

YouTube and Facebook said they also sponsor so-called counterspeech, encouraging users to create messages condemning violence and extremism and supporting voices of moderation.

After gathering a year of testimony from witnesses including senior police officers and intelligence officials as well as industry representatives, the committee concluded in its report that popular social-media platforms had become “the vehicle of choice in spreading propaganda and the recruiting platforms for terrorism.”

“They must accept that the hundreds of millions in revenues generated from billions of people using their products needs to be accompanied by a greater sense of responsibility and ownership for the impact that extremist material on their sites is having,” said the report.

Some terrorism experts took issue with the committee’s findings.

“Blaming Facebook, Google or Twitter for this phenomenon is quite simplistic, I’d even say misleading,” said Peter Neumann, director of the International Centre for the Study of Radicalization at King’s College London.

“Our research has shown that the vast majority of ISIS recruits that have gone to Syria from Britain and other European countries were recruited mainly via peer-to-peer interaction, not through the internet alone,” said Mr. Neumann.

While the committee has no formal powers to compel the government to act, its high-profile role can shape political debate. Nearly 1,000 British jihadists have traveled to the Middle East to fight alongside Islamic State militants, whose rise has in turn electrified local extremists, some of whom have plotted attacks at home.

British security officials have said they have foiled a number of terrorist plots. Terrorism-related arrests last year were 35% higher than the number in 2010, the report said. The U.K.’s terrorism threat level has stayed at its second-highest rung since late 2014, an unprecedented length of time.