Authorities in the US had been alerted to a potential assassination plot targeting former President Donald Trump by Iran several weeks before the fatal shooting at Saturday’s rally, highlighting concerns over the adequacy of Trump’s security measures, according to a report.

The report underscores that while there is no known link between Thomas Matthew Crooks and the Iranian government—viewed as a rogue state by the US—ahead of the rally, this warning about the threat appears to significantly contradict the level of protection afforded to Trump in Butler, Pa.

The Trump campaign has not yet addressed whether it was aware of the threat. Still, Anthony Guglielmi, an agency spokesman for the Secret Service, said, “Additional protective resources and capabilities have been added to the former President’s security detail.”

According to one source, earlier in this year’s election campaign, the Trump campaign had limited impromptu outdoor events where Secret Service personnel did not first screen participants.