Twitter accounts suspected of links to Russia have turned their attention to the contentious issue of US gun control in the wake of the mass shooting in Florida, researchers suggest.
Two companies which track online disinformation have found that bots began tweeting about the Parkland shooting shortly after the tragedy.
It included tweets about the mental health of suspect Nikolas Cruz.
Gun control is one of the most divisive issues in America.
Experts from New Knowledge – which tracks disinformation campaigns – said that suspected Russian bots are increasingly picking up on controversial issues.
"The bots focus on anything that is divisive for Americans – almost systematically," Jonathon Morgan, chief executive of New Knowledge told the New York Times.
He said that the gun control tweets followed a typical pattern of stoking both sides of an argument and casting public doubt on institutions such as the police or the media.
The Alliance for Securing Democracy, in partnership with research group the German Marshall Fund, also spotted similar tweets on its website, which tracks hundreds of Twitter accounts suspected of links to Russia.
It found that some were from human users, while others were suspected bots. It is believed that Russian bots used the hashtag #Parklandshooting to stoke tensions.
They included tweets about the mental health of suspected gunman Nikolas Cruz as well as suggestions that he searched for Arabic phrases before the attack.
The findings come as thirteen Russian nationals are charged with meddling in the US presidential campaign, as part of the FBI investigation led by Special Counsel Robert Mueller.
The indictment alleges that the Russians posed as Americans, opening financial accounts in their names, spent thousands of dollars buying political advertising and posted political messages on social media impersonating real citizens.