The U.S. Secret Service boosted security around former President Donald Trump after picking up intelligence in recent weeks of an Iranian plot to assassinate him, people familiar with the matter said, adding that the threat was separate from the attempt on his life last weekend.

There’s no indication of any link between the Iranian plot and Thomas Matthew Crooks, the 20-year-old man accused of shooting at and wounding Trump at a rally in Pennsylvania on Saturday.

Sniper teams killed Crooks seconds after he opened fire.