Fourteen travel agency owners or employees were indicted on human smuggling and other charges, accused of selling airline tickets they thought would be used by illegal immigrants, officials said.

Authorities said a records analysis showed six travel agencies sold tickets to an estimated 6,800 illegal immigrants in the United States since mid-2005. But Thursday's charges were connected only to the sale of tickets to undercover officers.

The travel agency employees were working independently of one another when they sold the tickets, said Bart Graves, a spokesman for the Arizona Department of Public Safety.

The undercover officers made it clear they were arranging travel for illegal immigrants and paid cash for dozens of one-way tickets across the nation, authorities said. The travel agencies offered advice on being discreet at airports, they said.

"They were so blatant about it because they hadn't been touched," Phoenix police Lt. Vince Piano said. "They would say, 'OK, you need to dress them like this. You need to walk them in through this. Does he have an ID?"'

The travel agency workers were charged under state human smuggling laws because they were facilitating the human trafficking, authorities said. Some faced charges of money laundering, conspiracy, racketeering and participating in fraudulent schemes.

All 14 have been arrested, Graves said. It was unclear Thursday evening whether any remained in custody.

"I am speechless," said 38-year-old Carmen Cortez of Phoenix, who is charged with human smuggling and illegally conducting an enterprise. "That's all I have to say."

Phoenix, 180 miles (289.7 kilometers) from the Mexican border, serves as a hub for transporting illegal immigrants across the country. Smugglers take immigrants to "stash houses" in Phoenix and make their travel arrangements.

If immigrants are to be flown to their destinations, smugglers buy tickets and, in many cases, drive them to McCarran International Airport in Las Vegas because of tight security at the Phoenix airport, investigators said.

The tip that led to the investigation came from a money laundering case that tracked the wire transfers of suspected immigrant smuggling proceeds, state Attorney General Terry Goddard said. The tip led police to a stash house where they found 30 illegal immigrants, plane tickets and itineraries.

Investigators found the names of travel agencies in the stash house, Goddard said.

The indictments mark another example of authorities trying to chip away at businesses that help smugglers transport their customers.

More than two years ago, nearly two dozen used-car-lot workers were indicted on charges of faking documents and committing other crimes to help sell vehicles to smugglers, known as "coyotes." Authorities said the vehicles were used to ferry drugs and illegal immigrants from Mexico.