San Francisco, May 21 (IANS): In the ongoing COVID-19 information war on Twitter which is often fought with the launch of new conspiracy theories, China has now gone on the offensive with about 90,000 tweets since the start of April.

Twitter is blocked in China so most of the tweets are churned out by diplomatic accounts as well as state media accounts.

According to a report in NBC News on Wednesday, the number of tweets from China's official handles on the microblogging platform has almost doubled since January.

Similarly, there has been a huge surge in the number of China's diplomatic Twitter accounts. From just 40 such accounts a year ago, their numbers have now reached to 135, said the report on the basis of an analysis by Bret Schafer, the digital disinformation fellow at Alliance for Securing Democracy at the German Marshall Fund of the United States.

The alliance in late March announced the expansion of the Hamilton 2.0 dashboard to include the tracking of Chinese government-backed information operations on social media, state-sponsored information websites, YouTube, and via official diplomatic channels.

Collecting data since November 2019, the China section of the dashboard has captured official government messaging on topics like the Hong Kong protests, Xinjiang, the trade war with the United States, the implementation of Huawei technology in Europe, and, most notably, the global outbreak of COVID-19.

In recent days, China has used Twitter to spread a conspiracy theory that the COVID-19 leaked from a US government lab, the NBC News report said.

"The #US keeps calling for transparency & investigation. Why not open up Fort Detrick & other bio-labs for international review? Why not invite #WHO & int'l experts to the US to look into #COVI19 source & response?" the spokesperson for China's Foreign Affairs Ministry wrote in a tweet on May 8.

The tweet refers to the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, Maryland.

In fact, China has been pushing this conspiracy theory for quite some time now, said the report.

According to the Alliance for Securing Democracy, official Chinese diplomatic and state-run media accounts tweeted the Fort Detrick conspiracy theory more than 30 times in the past two months.

China's more confrontational posture on COVID-19 represents a clear departure from its past behaviour, according to an analysis by the alliance.

In the early stages of the outbreak, official Chinese messaging largely focused on human-interest stories and reporting on the Chinese government's efforts to control the virus.

But from February 27, as the virus spread rapidly to Europe and the US, website data indicates that four of the top 10 most engaged articles on Facebook from Chinese state media outlets featured content that was critical of the Trump administration's response to COVID-19, the analysis showed.

On Twitter, Chinese diplomatic and embassy accounts promoted conspiracy theories from fringe websites, it added.