Correction: Earlier versions of this story, including the print edition of The Washington Post, said the arrested men were accused of carjacking. This version has been corrected.

Mary Dunkley had just gotten back from church choir practice when one of the carjackers ripped open the door to her Toyota Camry. The 70-year-old retired secretary said that as she spilled onto the ground outside her Landover townhouse, the man put a gun to her head and demanded that she give up her purse.

“He was telling me, ‘Let it go. Let it go,’ ” Dunkley said. “Someone else came around real quick and jumped in the passenger seat, and they were gone in seconds.”

The men who carjacked Dunkley on March 17 were professional thieves, members of a sophisticated transatlantic car theft ring, police said. The plan -- thwarted by Prince George’s County detectives who arrested two men they say are key players in the ring -- was to ship her 2009 silver Toyota thousands of miles to Lagos, Nigeria, authorities said.

While most cars are swiped for joy rides or cash from selling parts, authorities say the ring and others like it make up a complex, multimillion-dollar network.

Prince George’s police officials lauded the arrests of the ring’s high-ranking members. But they and other law enforcement authorities across the region acknowledged that the international car thieves are difficult to catch and the problem has become almost unsolvable.

“These guys are going to be replaced,” said Prince George’s Sgt. David Mohr, who works on the auto theft team.

Officials estimate that each year in the Washington area alone, hundreds of cars are stolen and shipped overseas. New York authorities announced last June that they had charged 17 people with stealing and shipping hundreds of luxury cars. Other D.C. area police officials and a spokesman for the FBI’s Baltimore Field Office said their detectives have worked similar cases.

Solomon Asare and Gabriel Awuzie, accused of being key players in the ring that stole Dunkley’s car, were arrested April 14 on car theft charges. Awuzie is scheduled to appear in court in May, and Asare in June.

“This has gone on and on and on, and it has become such an enterprise for them in the U.S.,” said Prince George’s County auto theft detective Luis Aponte. “There’s a major market for this.”

The ring’s bosses are usually based in African countries or other developing nations, where it is more difficult to find reasonably priced, mid- to high-end vehicles, authorities said. They order specific cars from middlemen in the United States, and then low-level thieves set out to get their cut.

In the Prince George’s ring, the thieves are paid according to the vehicles they carjack or steal — $1,500 for a Toyota Camry, $2,500 for a RAV4, $5,000 for a Porsche Cayenne, Aponte said. The middlemen handle the rest. They stash the stolen cars in parking lots or neighborhoods, waiting to see whether police are on their trail. Then they load the vehicles onto shipping containers bound for Africa, police said. The rings are especially prevalent in the D.C. area, police said, because of its proximity to ports.

Police say that in tracking Dunkley’s car, they were able to reach into one ring’s upper ranks.

Detectives on the Washington Area Vehicle Enforcement Team — a group of 10 auto theft investigators from Prince George’s and two from the Maryland State Police — long suspected Asare, 35, and Awuzie, 34, were involved in a ring, said Lt. Matt Meterko, who leads the group. But they were difficult to trace.

In March, detectives caught a break: Two men suspected in the carjacking of a Toyota Camry and told detectives Asare and Awuzie were scheduled to pick up a stolen car later that month.

Investigators secretly watched as a man talked to Asare in the parking lot of a Wal-Mart on Russett Green East in Laurel, then let Awuzie drive away in a Toyota Camry, Mohr said. Awuzie parked the Camry nearby, then Asare picked him up, Mohr said. They left the Camry behind, he said.

The moment was pivotal, police said, because it connected Asare and Awuzie to a car police suspected was stolen. Mohr said the Camry belonged to an Enterprise Rent-A-Car in Capitol Heights.

Detectives suspected the area near the Wal-Mart was a “cooling spot,” an area where the thieves would leave stolen cars until they were satisfied police were not trailing them.

Police began monitoring the car’s movements around-the-clock. Then, on March 29, they got their second big break: Anne Arundel County police found Dunkley’s Camry in the same Wal-Mart parking lot.

Investigators put a Global Positioning System tracker on Dunkley’s car, according to police charging documents. On March 31, a tow truck hauled the car to a warehouse on Hanna Street in Beltsville. Detectives began watching the warehouse.

Dunkley’s car and three other vehicles eventually were loaded into a faded red shipping container and hauled north, authorities said. Police stopped the load on April 13, just as it moved past the Fort McHenry Tunnel on I-95. They arrested Asare and Awuzie the next day, charging them with the theft of Dunkley’s Camry while they worked to put together a more comprehensive case.

In all, police seized six vehicles, four from the trailer and two that were in cooling spots elsewhere. Five were Toyotas, which detectives believe were requested because “they’re nice enough cars, but they’re not the high-end luxury cars that have the built-in tracking systems with them,” Mohr said.

Asare, an immigrant from Ghana, told police he lived in a modest Laurel townhome and worked as a trucker, according to court records. Awuzie, who was born in Kansas City, Mo., told police he lived in a Laurel apartment and worked at a Papa Johns Pizza, court records state. Since their arrests, both have been released on bond.

Awuzie declined to comment for this story. Asare, who also is charged with vehicle theft in Mongtomery County, did not return a written message seeking comment.

Richard Finci, Asare’s lawyer in an unrelated case, said charging documents do not identify his client as a higher-up in an international auto theft ring. He said he had not been officially retained to represent Asare in this case, and declined to comment further.

For Dunkley, it was no surprise that an international carjacking ring took her Camry. The thieves, she said, were so quick that she assumed they “must have been professional.”

The damage, Dunkley said, is lasting. She said the Camry was her “retirement car,” and she does not think she will be able to bring herself to drive it once she gets it back. She also had to replace her driver’s license and new prescription glasses, which were lost during the carjacking.

“They don’t know the problem they put people through,” Dunkley said. “It’s devastating.”

Staff writer Dan Morse contributed to this report.