NEW YORK (NYTIMES) - In January, a new group popped up on the messaging app Telegram, named after an Asian slur.

Hundreds of people quickly joined. Many members soon began posting caricatures of Asians with exaggerated facial features, memes of Asian people eating dog meat and images of US soldiers inflicting violence during the Vietnam War.

This week, after a gunman killed eight people - including six women of Asian descent - at massage parlours in and near Atlanta, the Telegram channel linked to a poll that asked, "Appalled by the recent attacks on Asians?" The top answer, with 84 per cent of the vote, was that the violence was "justified retaliation for Covid."

The Telegram group was a sign of how anti-Asian sentiment has flared up in corners of the Internet, amplifying racist and xenophobic tropes just as attacks against Asian Americans have surged.

On messaging apps like Telegram and on Internet forums like 4chan, anti-Asian groups and discussion threads have been increasingly active since November, especially on far-right message boards such as The Donald, researchers said.

The activity follows a rise in anti-Asian misinformation last spring after the coronavirus, which first emerged in China, began spreading around the world. On Facebook and Twitter, people blamed the pandemic on China, with users posting hashtags such as #gobacktochina and #makethecommiechinesepay.

Those hashtags spiked when former President Donald Trump last year called Covid-19 the "Chinese virus" and "Kung Flu."

While some of the online activity tailed off before the November election, its reemergence has helped lay the groundwork for real-world actions, researchers said.

The fatal shootings in Atlanta this week, which have led to an outcry over treatment of Asian Americans even as the suspect said he was trying to cure a "sexual addiction," were preceded by a swell of racially motivated attacks against Asian Americans in places like New York and the San Francisco Bay Area, according to the advocacy group Stop AAPI Hate.

"Surges in anti-Asian rhetoric online means increased risk of real-world events targeting that group of people," said Mr Alex Goldenberg, an analyst at the Network Contagion Research Institute at Rutgers University, which tracks misinformation and extremism online.

Negative Asian American tropes have long existed online but began increasing last March as parts of the United States went into lockdown over the coronavirus. That month, politicians including Republican Representatives Paul Gosar and Kevin McCarthy used the terms "Wuhan virus" and "Chinese coronavirus" to refer to Covid-19 in their tweets.

Those terms then began trending online, according to a study from the University of California, Berkeley. On the day Mr Gosar posted his tweet, usage of the term "Chinese virus" jumped 650 per cent on Twitter; a day later there was an 800 per cent increase in their usage in conservative news articles, the study found.

Mr Trump also posted eight times on Twitter last March about the "Chinese virus," causing vitriolic reactions. In the replies section of one of his posts, a Mr Trump supporter responded, "U caused the virus," directing the comment to an Asian Twitter user who had cited US death statistics for Covid-19. The Mr Trump fan added a slur about Asian people.

Representatives for Mr Trump, Mr McCarthy and Mr Gosar did not respond to requests for comment.

Misinformation linking the coronavirus to anti-Asian beliefs also rose last year. Since last March, there have been nearly 8 million mentions of anti-Asian speech online, much of it falsehoods, according to Zignal Labs, a media insights firm.

In one example, a Fox News article from April that went viral baselessly said that the coronavirus was created in a lab in the Chinese city of Wuhan and intentionally released. The article was liked and shared more than 1 million times on Facebook and retweeted 78,800 times on Twitter, according to data from Zignal and CrowdTangle, a Facebook-owned tool for analysing social media.

By the middle of last year, the misinformation had started subsiding as election-related commentary increased. The anti-Asian sentiment ended up migrating to platforms like 4chan and Telegram, researchers said.

But it still occasionally flared up, such as when Dr Li-Meng Yan, a researcher from Hong Kong, made unproven assertions last fall that the coronavirus was a bioweapon engineered by China. In the United States, Dr Yan became a right-wing media sensation. Her appearance on Tucker Carlson's Fox News show in September has racked up at least 8.8 million views online.

After the shootings in Atlanta, a doctored screenshot of what looked like a Facebook post from the suspect circulated on Facebook and Twitter this week. The post featured a miasma of conspiracies about China engaging in a Covid-19 cover-up and wild theories about how it was planning to "secure global domination for the 21st century."

Facebook and Twitter eventually ruled that the screenshot was fake and blocked it. But by then, the post had been shared and liked hundreds of times on Twitter and more than 4,000 times on Facebook.