PHOENIX >> Federal law enforcement authorities are in the process of seizing online classified site Backpage.com and its affiliated websites known for listing adult escort services.

A notice that appeared this afternoon at Backpage.com says the websites are being seized as part of an enforcement action by the FBI, U.S. Postal Inspection Service and the Internal Revenue Service.

The notice doesn’t characterize or provide any details on the nature of the enforcement action. It said authorities planned to release information about the enforcement action later Friday.

Backpage.com lets users create posts to sell items, seek a roommate, participate in forums, list upcoming events or post job openings. It also known for listings adult escorts and other sexual services, and authorities say advertising related to those services has been extremely lucrative.

Last year, the creators of the website were charged with money laundering in California.

State prosecutors in California have said the website’s chief executive Carl Ferrer and founders Michael Lacey and James Larkin illegally funneled money through multiple companies and created various websites to get around banks that refused to process transactions. They have pleaded not guilty.

Lacey and Larkin are former owners of the Village Voice and the Phoenix New Times, but retained ownership of Backpage.com.

A decade ago, they were arrested by then-Sheriff Joe Arpaio’s office in 2007 for publishing information about a secret grand jury subpoena demanding information on its stories and online readers.

They won a $3.75 million settlement from county government as a result of their now-discredited arrests.