A day after the deadliest school shooting in the U.S. in five years, Russian bots began inundating Twitter with gun-related tweets. Shooting-related terms dominated the trending hashtags and trending topics at Hamilton 68, which is a website created by the bipartisan security organization Securing Democracy to track activity from Twitter accounts it's identified as linked to Russian influence campaigns.

Popular terms included "guncontrol," "gunreformnow," "floridaschoolshooting" and "nikolascruz," which refers to the suspect in the shooting.

At Botcheck.me, a website that tracks 1,500 political propaganda bots, the dashboard for most-popular hashtags in 24 hours from Wednesday to Thursday evening was dominated by terms such as "guncontrol," "parkland" and "gunreformnow." Ash Bhat, one of the project's creators, wouldn't speculate on who was behind the bots his site tracks but told Wired the bots amplify the hashtags until they're eventually adopted by human users.

Get Breaking News Delivered to Your Inbox

"Over time, the hashtag moves out of the bot network to the general public," he said.

The figures from the bot-tracking sites illustrate how Russian meddlers continue to manipulate the platform following efforts to use social networks to sow discontent during the 2016 U.S. election. Those efforts targeted highly politicized social issues such as immigration, guns and LGBT rights.

Twitter has said it detects about 450,000 "suspicious" logins a day that may be bots or computer programs created to automatically post and respond to things on Twitter. It has also said it's identified 3,814 accounts linked to the Internet Research Agency, which was the seat of the Russian propaganda effort during the election.

Prosecutors on Thursday charged Cruz, a 19-year-old former student at the school, with 17 counts of premeditated murder after the rampage Wednesday at Marjory Stoneman Douglas High School. Fifteen other students were wounded.

Twitter didn't immediately respond to a request for comment.

This article originally appeared on CNET.