LOS ANGELES (AFP) - A disgruntled airport security screener was arrested in California on Tuesday in connection with threats made against Los Angeles International Airport ahead of the 9/11 attacks anniversary, authorities said.

Nna Alpha Onuoha, 29, was detained on late Tuesday by members of the Los Angeles Joint Terrorism Task Force after triggering an alert at the airport earlier in the day which prompted certain terminals to be evacuated, the FBI said in a statement.

Onuoha had resigned from his job as a Transportation Security Administration screener on Tuesday after recently being suspended from the position, FBI spokesman Laura Eimiller said in a statement.

Los Angeles Police Department bomb squad officers were called on earlier Tuesday after Onuoha left a package at the TSA's LAX headquarters addressed to an employee.

The package was harmless but contained a letter in which Onuoha spoke of his "disdain for the United States".

Later Tuesday Onuoha is believed to have called the TSA, warning that certain terminals at LAX should be evacuated, Ms Eimiller said.

"The terminals in question were cleared by law enforcement personnel and no threat to the airport was found," Ms Eimiller said.

When anti-terrorism officers raided Onuoha's apartment they discovered a note taped inside a closet "containing an unspecified threat citing the 9/11/13 anniversary".

Onuoha was later arrested and was being held on suspicion of making threats, pending further investigation, the FBI said.