Connecticut police and the FBI are knocking on doors, combing the woods with dogs and searching by air for missing 13-year-old Isabella Oleschuk.
The Orange, Conn., girl was last seen Saturday night at her parent's home. Isabella is partially deaf and normally uses a hearing aid. Her hearing aid was left behind, prompting concerns among rescuers that she might not be able to hear people calling her name.
When ABC News reached Isabella's grandfather by phone, he said that the family is "anxiously awaiting her safe return."
Isabella's parents reported her missing early Sunday morning.
Police have issued a Silver Alert, which indicates that her disappearance is "mysterious" but not necessarily an abduction. Fliers being handed out throughout the town characterize the seventh-grader as an "endangered runaway."
Police have enlisted the help of the FBI, fire department and even police cadets to assemble a team of 100 that has fanned throughout the town of less than 14,000 people.
A jogger spotted a young couple early Sunday morning near Racebrook School, a mile from Isabella's home, police said
"The young female did fit Isabella's description, looked similar to Isabella. ...This young female was accompanied by a young male who was slightly taller than her and had dark hair," Orange Police Chief Robert Gagne said at a news conference late Monday. "They were holding hands. There didn't appear to be any kind of distress."
Police officials did not return calls asking for additional comment.
Isabella is described as 5-feet 4-inches tall, 120 pounds with blue eyes and shoulder-length blond hair. She was last seen wearing a light blue jacket, brown-felt hooded cap and black rain boots.
There have also been reports that the girl was seen at a restaurant and a grocery store Monday night, ABC Affiliate WTNH reported.
"We are not going to stop until we find Isabella," Chief Gagne said at the news conference. "My hope is that when this is all over we can find her safe."
Prayer Vigil Held for Missing Connecticut Girl
A prayer vigil was held Monday for Isabella by Orange Congregational Church, the church where the girl was baptized and her parents were married.
"We are part of a very close-knit community here," Orange resident Willie Ayala told WTNH.
Ayala's daughter, Andriana, is one of Isabella's classmates.
"We've just been trying to keep hope, because we know we are going to find her," Andriana told WTNH.
Pastor Tod King said that a candle will be lit in the church each day that Isabella remains missing.
If you have any information on the whereabouts of Isabella, contact Orange Police at (203) 891-2130.
ABC Affiliate WTNH contributed to this report.