State and local authorities suspect that they've uncovered a shadowy organization that has been terrorizing Asian-Americans in Philadelphia and Delaware County with a series of gunpoint robberies and home invasions over the past two years.

Two Southwest Philadelphia men were charged yesterday with mugging a Middletown couple last weekend after the men tailed their Mercedes-Benz from the Springfield Mall to their home on Lenni Road.

"These guys were basically surfing for their victims on the highways here in Delaware County," said State Police Capt. David Young.

The county saw three similar cases this week - two in Marple Township and one in Collingdale Borough - involving Asian business owners, which prompted District Attorney G. Michael Green yesterday to sound the alarm.

"Business owners, and especially Asian and Asian-American shopkeepers, are advised to take care in the handling of cash," Green said. "It is suggested that shopkeepers vary their routines."

On Monday, three armed bandits broke into a home on Hampshire Drive in Marple and beat and robbed a man and his wife, who are in their mid-60s and own a business in West Philadelphia. Two nights later, a South Korean woman who had just closed her shop in Upper Darby was robbed outside of her Marple home of a briefcase filled with about $1,500 in cash. Police believe the victims were followed from their respective stores.

In Collingdale early yesterday, masked gunmen climbed into the apartment above the China Moon Restaurant on MacDade Boulevard where the restaurant owners live. An undetermined amount of money was stolen. One shot was fired, but no injuries were reported, said police Chief Robert Adams.

The two men busted yesterday - Shawn Davis of Caesar Place near 80th Street and Charon Humphrey of Wheeler Street near Claymont - have been charged only in the Middletown case. They have admitted to stealing about $5,000 in cash, credit cards and jewelry, including the pregnant woman's wedding ring, police said.

But Green, who was joined yesterday by Capt. Benjamin Nash and Lt. John Walker of Southwest Detectives, said the two men likely "played a role" in at least one of the Marple cases and could be tied to a large crew that is responsible for dozens of armed robberies in Philadelphia and Delaware County.

Authorities were interviewing several other suspects yesterday, and the FBI has been assisting in the case.

"Those persons who are of interest to us have indicated that Asian and Asian-American persons were targeted," Green said. "They were targeted, operating either late-model, high-end motor vehicles or as shopkeepers."

Neither Green nor Young would comment on why the men are allegedly going after a specific ethnic group.

"There are connections, clearly, to what has been happening in the Southwest part of Philadelphia," said Nash, who declined to specify how many cases city detectives believe are linked to the suburban incidents. *