LOS ANGELES » Authorities are examining a website they say is linked to an arrested airport security screener that contained letters declaring America would be "reduced to nothing" by events "greater than 9/11."

The letters were posted on a website apparently operated by Nna Alpha Onuoha, 29, who was charged Wednesday with one count each of making a false threat and making threats affecting interstate commerce, the day after quitting his job with the Transportation Security Administration at Los Angeles International Airport.

The site under investigation includes Onuoha’s name and a birth date that matches public records for him. It contains letters celebrating Jesus and Israel, condemning al-Qaida and lamenting that Satan has corrupted so many. There also are photos of Onuoha posing with crosses.

In one posting attributed to Onuoha, he said a message would be released Sept. 11 and America "will be reduced to nothing."

"Do not expect another 9/11," it said. "What will unfold on this day and on the days ahead will be greater than 9/11."

That passage is part of a lengthy letter apparently written to the father of a 15-year-old girl whose treatment by Onuoha during screening at LAX in June led the TSA to suspend him. Onuoha was upset by the girl’s attire and said, "You’re only 15, cover yourself."

The incident drew attention when the girl’s father, Mark Frauenfelder, wrote about it on boingboing, the blog he founded. He said his daughter was humiliated and shamed. He posted a photo of her in the outfit, modest by modern standards, and said he had complained to TSA.

A federal official confirmed the incident was the reason Onuoha was suspended for a week in July. The official spoke on condition of anonymity because he wasn’t authorized to talk about the case publicly.

The letter apparently meant for Frauenfelder was dated Aug. 25. In it, Onuoha was unapologetic.

"If you need an example on how to properly dress your fifteen year old daughter before you send her out on a world tour in this world ruled by satan, you should look up to Muslim women," the letter said.

TSA spokesman Ross Feinstein declined to comment, referring questions to law enforcement investigating the matter.

Onuoha, originally from Nigeria, had worked for TSA since 2006, FBI spokeswoman Laura Eimiller said.

He showed up at LAX on Tuesday afternoon, resigned from his job and returned several hours later to leave a package at TSA’s airport headquarters that was addressed to a manager.

A bomb squad found no explosives or harmful contents in the package but discovered an eight-page letter in which Onuoha expressed disdain for the U.S. and referenced the event that led to his suspension, Eimiller said.

Later Tuesday, a man believed to be Onuoha made two phone calls to TSA saying certain airport terminals should be evacuated, Eimiller said. During one call, the man told an employee he would "be watching" to see if authorities evacuated the terminals as instructed.

The threats prompted a brief shutdown of parts of LAX on Tuesday.

Then on Wednesday, packages mailed to a TSA office and a staffer at an apartment complex for military veterans near the airport where Onuoha lives brought brief evacuations at both places until it was determined the packages contained only papers, airport and Inglewood police said.

In a search of Onuoha’s apartment, police found a handwritten note entitled "9/11/2013 THERE WILL BE FIRE! FEAR! FEAR! FEAR!" and containing unspecified threats that cited the anniversary of the terror attacks, authorities said.

An FBI affidavit says Onuoha told investigators he didn’t mean the calls to the airport to be threats and he had no violent intentions. He said he wanted to start preaching in the streets beginning Wednesday, the anniversary of the 9/11 attacks.

Those who knew Onuoha saw no signs of any problems with him.

"There was never any indication of anything at all. Again, a big surprise," said Larry Vaughan, property manager at Onuoha’s apartment complex.

Onuoha made his initial court appearance Wednesday, and his next court hearing was scheduled for Monday. If convicted, he faces up to 15 years in prison.

Defense attorney Samuel Josephs declined to comment, saying he had not had time to review all the documents in the case.

AP Special Correspondent Linda Deutsch and AP writer Raquel Maria Dillon contributed to this report.