(Reuters) - A woman believed to have been kidnapped for ransom in southern Washington state was still missing on Saturday, a day after authorities arranged to meet the demand and then arrested a suspect, police said.

Sandra Harris, 69, was reported missing on Friday by her husband, who called authorities to say she was abducted from the couple's home in Kennewick, a town about 200 miles (322 km) southeast of Seattle, Kennewick police said in a statement.

Kennewick police and agents from the Federal Bureau of Investigation made contact with a suspect in Harris' abduction, Kennewick police said in a statement.

The suspect, a 49-year-old woman, was apprehended on Friday night shortly after an undisclosed sum of money was paid, but Kennewick police Sgt. Bryan Weatherbee said the victim had not yet been located on Saturday night. He declined to provide any further information.

Police said in the statement they did not believe the kidnapping was random, but that the family had actually been targeted, and that they were still working to determine a motive.

FBI officials in Seattle could not be reached about the case.

(Reporting by Alex Dobuzinskis and Chris Michaud; Editing by Shri Navaratnam)