OSWEGATCHIE, N.Y. -- Police have released a sketch of one of the two Amish girls they believe were abducted at a roadside stand in northern New York Wednesday, as searchers scoured the countryside near the Canadian border for the missing children.

Police have received "numerous leads" and deputies, state troopers, forest rangers and U.S. Border Patrol agents were part of the ongoing search for 7-year-old Delila Miller and 12-year-old Fannie Miller, St. Lawrence County Sheriff Kevin Wells said.

Because the Amish tend to shun modern technology, police had no photographs of the girls, police said. The St. Lawrence County Sheriff's department released the sketch Thursday afternoon of 12-year-old Fannie.

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The girls' family decided to allow the release of the sketch of Fannie out of concern for their daughter, reports CNYCentral.com. But the family also chose not to have investigators develop a sketch of Delila because of their beliefs, reports the website.

Officials issued an Amber Alert for the two girls after police say they were abducted around 7:30 p.m. Wednesday in the rural town of Oswegatchie on the Canadiana border, about 130 miles north of Syracuse.

The girls went to wait on a customer at the family's roadside stand, officials said. A witness saw a passenger in a vehicle put something into the back seat, and when the vehicle drove off the children were gone, police said.

Wells told reporters Thursday afternoon the girls had no apparent family issues that would lead investigators to believe the abductor could be someone close to them.

He described the family as a "positive group."

"They're resilient," he said.

Wells said both girls speak Pennsylvania Dutch as their first language. The girls have heavy accents, and Fannie Miller speaks English, reports WSYR.

The focus of the search continues to be St. Lawrence County, Wells told reporters. The rural, heavily wooded area has posed challenges for search crews, however.

"That's why air support and sheer manpower, boots on the ground to do the searches, is very important," Wells said.

Wells said the local Amish community was helping law enforcement by getting the word out despite a culture that avoids modern conveniences.

"They communicate amazingly among themselves as far as getting the word out, " he said. "People we were stopping last night already knew what was going on."

The girls were last seen wearing dark blue dresses with blue aprons and black bonnets, but police said it's possible they could have changed their clothes by now.

Both girls have brown hair and brown eyes. Fannie is approximately 5 feet tall and weighs 90 pounds; she is also cross-eyed. Delila is about 4 feet tall and 50 pounds; she has a round scar on her forehead and is missing front teeth.

Police are reportedly talking to several potential witnesses, and dive teams have searched the Oswegatchie River, reports CNYcentral.com. The dive teams were no longer searching on Thursday afternoon, Wells said.

Police urged the public to contact them with any information. They're hoping to speak with anyone who may have seen the girls from 6 p.m. Wednesday evening on.

The rural county is home to New York's second-largest Amish population, which has grown by some 10,000 upstate over the past decade, drawn by productive land and property prices lower than in Pennsylvania.

The sheriff said police are looking for a white four-door sedan a witness reported seeing at the farm stand when the girls disappeared.

Anyone with information is urged to contact the St. Lawrence County Sheriff's Department at (866) NYS-Amber.