The Justice Department has unsealed criminal charges against three Iranian operatives suspected of hacking Donald Trump’s presidential campaign and disseminating stolen information to media organisations.

The Trump campaign disclosed on August 10 that it had been hacked and said Iranian actors had stolen and distributed sensitive internal documents.

Multiple major news organisations said they were leaked confidential information from inside the Trump campaign – including Politico, The New York Times and The Washington Post – and declined to publish it.

US intelligence officials subsequently linked Iran to a hack of the Trump campaign and to an attempted breach of the Joe Biden-Kamala Harris campaign.

They said the hack-and-dump operation was meant to sow discord, exploit divisions within American society and potentially influence the outcome of elections that Iran perceives to be “particularly consequential in terms of the impact they could have on its national security interests”.

Last week, officials also revealed that the Iranians in late June and early July sent unsolicited emails containing excerpts of the hacked information to people associated with the Biden campaign. None of the recipients replied.

The Harris campaign said the emails resembled spam or a phishing attempt and condemned the outreach to the Iranians as “unwelcome and unacceptable malicious activity”.

The indictment comes at a time of heightened tensions between Washington and Tehran as Iran-backed Hezbollah and Israel escalate attacks against each other, raising concerns about the prospect of an all-out war, and as US officials say they continue to track physical threats by Iran against a number of officials including Mr Trump.