The FBI said Monday it's investigating the source of an online threat referencing Houston Stadium but has determined there is no credible danger.
Local news source Chron reported that the online threat surfaced as Houston Stadium prepared to host a FIFA World Cup Round of 32 match between Brazil and Japan.
Brazil won Monday's game 2-1 to advance to the soccer tournament's next round.
"FBI Houston is aware of a threat to Houston Stadium circulating online. We are working with our local, state, and federal public safety partners to investigate who is behind the communication," the agency said in a statement.
"At this time, there is no credibility to the threat. We continue to analyze and assess the situation," the statement added.
FBI Houston spokesman Connor Hagan told KHOU 11 the online threat was sent Monday morning to multiple businesses and news organizations and referenced Houston Stadium.
Hagan said investigators determined the threat was not credible but are continuing efforts to identify its source.
The FBI asked area residents to stay alert. "We urge the public to remain vigilant and report any suspicious activity or individuals to law enforcement immediately," the agency said.
The Houston FBI office also posted on Monday that illegal drone flights are drawing the attention of law enforcement agencies supporting the World Cup action there.
The agency posted on Facebook, "Reminder: Houston #FIFAWorldCup matches, Fan Fest, and related events are No Drone Zones!"
"As multiple individuals recently learned, flying unauthorized drones in restricted Houston 2026 World Cup airspace will result in federal charges and up to $100,000 in fines!" the post stated.
Three people are facing federal drone flight-related charges in Houston. One was charged after receiving a warning.
The Islamic State is encouraging supporters to take advantage of a "golden opportunity" to commit lone-wolf terrorist attacks in the 11 U.S. cities hosting World Cup matches.
In a recent editorial in its weekly newsletter, ISIS described soccer's largest tournament as a "feast of filth" and a "deadly weapon" in the hands of "Crusaders" and Jews, with a goal of undermining Muslim faith and morals, according to a translation.