Social media giant Twitter on Thursday released a new archive of state-backed propaganda from accounts it has banned based in Iran, Russia, Spain and Venezuela.
The US platform said it had taken the material off its network, but would make it available to researchers and investigators studying online threats.
Tech firms have been accused of allowing political propagandists to use social media to hijack elections, poison online debate and smear their opponents.
But Twitter, in a blog post by head of site integrity Yoel Roth, said "transparency is core to our mission" and vowed to fight "misleading, deceptive, and spammy behaviour".
Thursday's release was the firm's third such archive, representing more than 30 million tweets and a terabyte of media data from just under 5,000 suspected accounts.
Twitter has removed 4,779 accounts it believes "are associated with - or directly backed by - the Iranian government."
Most of these were found to be spreading news stories angled to support Iranian geopolitical interests or to be fake user profiles designed to manipulate online debate.
A smaller sub-group, originating in Iran, exclusively "engaged with discussions related to Israel".
Twitter has previously targeted alleged Russian bots, and this archive contains four more accounts that the firm believes are associated with the Internet Research Agency (IRA).
This St Petersburg-based "troll factory" has been accused of working with Russian intelligence to influence Western votes, notably US President Donald Trump's election campaign.
Investigations into the Russian agency also led Twitter's security team to 33 more accounts linked to a previously known group of 764 Venezuelan fake users.
"Our further analysis suggests that they were operated by a commercial entity originating in Venezuela," the post said.
And in Spain, Twitter has taken down 130 allegedly fake accounts apparently set up to push the views of Catalan separatists.
"We believe the public and research community are better informed by transparency," Roth said.
On Friday, EU justice commissioner Vera Jourova and security commissioner Julian King are to brief reporters on European efforts to fight political disinformation.