An Amber Alert that triggered a nationwide search for two missing children ended in Idaho Springs on Thursday when the youngsters were found riding on a Greyhound bus that had broken down on Interstate 70.

Idaho Springs police arrested John Baugher, 34, who is accused of failing to return his 2-year-old son Lars and 4-year- old daughter Remi following a court-authorized visit, according to the FBI's Seattle office.

The arrest went without incident and both children were unharmed and were scheduled to be reunited with their mother, an FBI spokeswoman said.

Police in Walla Walla, Wash., issued an Amber Alert on Sunday. Authorities later traced Baugher and his children to a bus that left Salt Lake City on Thursday bound for Hartford, Conn.