Experts warn of ‘soft target’ vulnerabilities and intelligence gaps as federal agencies prepare to secure 78 matches across 11 cities

Fifa World Cup matches set to be held across the United States face heightened terrorism risks, with experts warning that vulnerabilities are being amplified by the US-Israel conflict with Iran and a depletion of counter-terrorism expertise within federal law enforcement.

The biggest threat stems from homegrown violent extremists, often lone actors that may have become radicalized online by extreme political views or jihadists such as the Islamic State (Isis), said four counter-terror experts interviewed.