WASHINGTON • Twitter on Tuesday said it had suspended a number of accounts that claimed to be owned by black supporters of US President Donald Trump and his re-election campaign, saying the accounts broke its rules on spam and platform manipulation.

"Our teams are working diligently to investigate this activity and will take action in line with the Twitter rules if tweets are found to be in violation," a spokesman said.

A Reuters review of some of the suspended accounts showed they often used images of real people that did not match their names and posted identical language in their messages, including the phrase: "YES IM BLACK AND IM VOTING FOR TRUMP!!!"

The accounts sometimes claimed to be owned by military veterans or members of law enforcement.

Associate Professor Darren Linvill, a social media disinformation researcher at Clemson University who said he had been tracking the accounts since last Saturday, found more than two dozen that collectively had 265,000 retweets or Twitter mentions.

The accounts ranged in size but some had tens of thousands of followers, he said.

Twitter declined to specify the number of accounts suspended or to comment beyond its statement.

The company's policy against platform manipulation and spam bans coordination among accounts to artificially influence conversation, including the use of multiple or fake accounts.

According to Prof Linvill, some of the accounts used photos of black American men that had appeared in news articles. Some used identical images of Mr Trump as their header image.

Prof Linvill also said most of the accounts were created in 2017, but had become more active in the past two months. All the accounts he was tracking in the group had now been suspended, but the damage was already done, he said.

"It doesn't matter if Twitter's shutting you down in four days, they've already had their impact," Prof Linvill said.

REUTERS