Specious theories designed to implicate Ukraine and the United States in connection with the late March terror attack in Russia are spreading on China’s state media outlets and on its heavily censored social media platform Weibo.

False claims that paint Kyiv and Washington as masterminds of the attack have fueled debate in Russia even after Islamic State-Khorasan — also known as IS, IS-K, ISIS and Daesh — claimed responsibility for killing at least 143 people and injuring nearly 200 at the Crocus City Hall music venue in suburban Moscow.

In China, an editorial in the state-run Global Times insinuated that “many observers linked the incident to the ‘hybrid war’ form of the Russia-Ukraine conflict.”

“Some Western thinkers have begun to speculate whether Washington had played a role in this terrorist attack,” it said without elaborating.

Without citing names or clear attribution, the Global Times repeated Russia’s false accusations that the U.S. failed to share “key intelligence” that could have helped Russian security services prevent the attack.

In fact, the U.S. warned the Russian authorities two weeks before the attack and shared appropriate intelligence, as it would do “for any other country,” John Kirby, White House national security communications adviser, told VOA.

“We provided useful, we believe, valuable information about what we thought was an imminent terrorist attack,” Kirby said. “We also warned Americans about staying away from public places like concert halls. So, we were very direct with our Russian counterparts appropriately to make sure that they had as much useful information as possible.”

Addressing a Russian intelligence agency board meeting three days before the attack, Russian President Vladimir Putin dismissed the U.S. warning as “outright blackmail” intended “to intimidate and destabilize our society.”

The Global Times also criticized Washington for being “slow to condemn the incident in a timely manner, which shocked the international community.”

In fact, the United States was among the first nations to condemn the Moscow attack, and on March 30, U.S. Ambassador to Russia Lynne Tracy placed flowers at the site.

With the Chinese Communist Party’s tight censorship of online content, contrarian views are quickly taken down, and the lack of independent media leave disinformation spread by state-controlled news outlets unchallenged.

Some, however, have voiced skepticism.

“I personally think it’s unlikely that the United States was behind this terrorist attack,” Jin Canrong, a scholar of international relations with an established “anti-American” reputation, wrote on Weibo.

The comments by Jin, who is a professor at the Renmin University of China, provoked heated reaction, with some Weibo users accusing him of being a U.S. sympathizer.

Since the attack, conspiracy theories echoing Russian propaganda have dominated the narrative on Weibo, typically boosted by anonymous pro-Russian and pro-Chinese influencers with millions of followers.

Weibo influencer Drunk Rabbit posted to his nearly half a million followers: “It is no wonder that the Russian people do not believe that this was done by IS. They all firmly believe that Ukraine and its masters who are at war with Russia planned and carried out this atrocity.”

To prove the point, the user posted two side-by-side video clips showing former U.S. Presidents Barak Obama and Donald Trump.

Drunk Rabbit​’s caption read: “Obama: ‘We trained ISIS,’” and “Trump: ‘Obama was the founder of ISIS.’”

“Both former presidents have confirmed that the United States is the creator of ISIS,” Drunk Rabbit continued. “Regarding the terrorist attack on the Moscow Concert Hall in Russia, what other evidence is needed?”

The quotes by Obama and Trump, however, are taken out of context and, in the case of Obama’s remarks, twisted to mean the opposite of what he said.

Trump’s claim has been debunked by fact-checkers and terrorism experts who traced Islamic State’s roots to 2002, six years before Obama was elected president, and Trump himself walked the remark back, calling it “sarcasm.”

It is not out of character for the Chinese state and social media to echo Russian propaganda and disinformation, especially when it targets the United States.