New York CNN Business  — 

Facebook on Tuesday said it had shut down more than 150 fake accounts it determined were run from China, including accounts posting about November’s US presidential election.

Facebook said the scale of the operation was small, but it is the first time the company has made public details about an operation it found to be run from China that had been posting about the US election.

The accounts “posted content both in support of and against presidential candidates Pete Buttigieg, Joe Biden and Donald Trump,” Nathaniel Gleicher, Facebook’s head of security policy, wrote in a post on the company’s website.

Graphika, a social media analytics company commissioned by Facebook to study the network of accounts, wrote in its report Tuesday, “In 2019-2020, the operation began running accounts that posed as Americans and posted a small amount of content about the US presidential election. Different assets supported President Donald Trump and his rival Joe Biden; one short-lived group supported former presidential candidate Pete Buttigieg. The operation did not single out either candidate for preferential treatment. Many of the accounts in this phase of the operation were barely active.”

Facebook did not say if the accounts were tied to the Chinese government, only that the accounts were run from China’s Fujian province. The company did point out, however, that the accounts had been posting about “Beijing’s interests in the South China Sea.”

Graphika said accounts in the network had defended Beijing.

Gleicher stressed that most of the activity focused on South East Asia and only a very small amount of activity focused on the 2020 election.

However, there was a sense of urgency in Facebook’s announcement Tuesday.

The company normally discloses takedowns like this once a month — the next announcement is not due for another week or two.

Gleicher told reporters Tuesday that given the nature of the company’s findings “we thought that it was important that people should be aware of what we are seeing.”

Graphika said the operation exposed Tuesday began in late 2016 by posting about Taiwan. By 2018, it was posting about the Philippines and argued in favor of Chinese influence in the region. Also in 2018, the operation created a collection of pages that posted in defense of China’s actions in the South China Sea.

Graphika said that when the operation began to focus on the United States it “used fake accounts to pose as politically engaged users on both sides of the partisan divide.” The company said the group did not build a viral following in the US.

The operation included one Facebook Group called Biden Harris 2020, which had 1,700 members.

“The way that it set up pages and accounts to support Trump, Biden, and Buttigieg did not suggest an attempt to support one candidate,” Graphika concluded.

It added: “It is possible that the intention was to further polarize America’s political landscape by affirming each side’s view of the other, but in that case, it is strange that the operation paid no attention to more progressive groups and candidates, such as senators Bernie Sanders and Elizabeth Warren.”

Ben Nimmo, head of investigations at Graphika told CNN, “The US-focused content was the least and last part of the operation. It ran one group each to support President Trump, Vice President Biden and Pete Buttigieg; all together, they had under 2,000 members. Some of their fake accounts did not engage with political content at all, and liked content from the US military instead. Most of the US-focused assets were taken down when they were a few months old, so they didn’t have time to build a substantial audience.”

Earlier this month, Facebook announced it had recieved a tip from the FBI that led it to exposing a fake leftwing news outlet posting about the 2020 election that Facebook determined was linked to people involved in a Russian troll group.