A 23-year-old Las Vegas man who authorities say worked as a security guard has been arrested and accused of plotting to firebomb a synagogue or a bar catering to LGBTQ customers.

A U.S. magistrate judge on Friday ordered Conor Climo to remain in federal custody following his arraignment on a federal firearms charge that could get him 10 years in prison and a $250,000 fine.

Climo's court-appointed attorney didn't immediately respond to messages.

U.S. Attorney Nicholas Trutanich says Climo was arrested Thursday, after an FBI-led anti-terrorism investigation and the discovery at Climo's home of diagrams and items that could make bombs.

Court documents say Climo communicated by encrypted internet chat with people identified as white supremacists, and told an FBI informant recently that he was scouting places to attack.