An Oregon high school educator is now incarcerated following an undercover operation that prompted charges of online sexual offenses against minors. 

The Portland Police Bureau reported that 36-year-old Oscar Armando Ramirez supposedly engaged in lewd conversations with someone he thought was a 13-year-old girl while employed as a high school teacher. 

In reality, Ramirez was communicating with an undercover law enforcement officer who was pretending to be a child as part of a sting operation aimed at online predators, officials stated. 

Oscar Armando Ramirez was working as a high school teacher when police say he exchanged lewd messages with an undercover police officer posing as a minor.  (iStock)

The investigation did not reveal any crimes involving students at the high school or any other children, police said.  

Ramirez pleaded not guilty to the charges and is set to return to court on Tuesday, according to KOIN 6.

Fox News Digital was unable to immediately locate an attorney for Ramirez.