Authorities in Tennessee continue to search for a missing mother of four whose vehicle was found abandoned with a flat tire.

Karen Johnson Swift, 44, of Dyersburg, Tenn., was reported missing on Sunday by her husband.  Her white 2004 Nissan Murano was later found on a nearby road, but authorities have been unable to locate her cell phone.

Dyer County Sheriff Jeff Box told The State Gazette that the investigation is being treated as a missing person case and there have not been any signs of foul play. On Tuesday, a Tennessee Highway Patrol helicopter equipped with a heat-sensor performed an aerial search of the area.

"We are actually rechecking some of the areas we were in and we are also broadening our search," Box told the newspaper.

Swift filed for divorce from her husband in early October, her friends told MyFoxMemphis.com.

"I'm really praying for the family," said Heather Davis. "I hope everything is fine and that she comes home."

Swift is described as 5 feet 5 inches tall with green eyes and blonde hair. She weighs about 140 pounds. Anyone with information regarding her whereabouts is asked to contact the Dyer County Sheriff's Office at (731) 285-2802.

The Associated Press contributed to this report.

Click here for more on this report at MyFoxMemphis.com.