SEOUL, July 9 (CGTN) - South Korean police are searching for Park Won-soon, the mayor of Seoul, after his daughter filed a missing person's report for him on Thursday.

The Seoul Metropolitan Police Agency said officers were searching for him around Sungbuk-dong, a district in northern Seoul, where his phone signal was last detected.

Drones and police dogs have also been mobilized for the search operation.

Park's daughter notified the police around 5:17 p.m. local time that he "had left home four to five hours ago after leaving words like a will, with his phone currently off," according to Yonhap News Agency.

According to some local reports, Park left the official residence at around 10:44 a.m. wearing a black hat and backpack and group texted reporters to cancel a scheduled appointment.

The Seoul government earlier said one of Park's appointments, which was scheduled at 4:40 p.m., was canceled due to "inevitable circumstances."

According to South Korean television and radio network company SBS news, a former secretary of the mayor had filed a sexual harassment complaint against Park with the police before his disappearance.

But the police have not confirmed the complaint so far.

Park, 64, who has been the mayor of Seoul since 2011, is seen as a potential presidential hopeful for the liberals in the 2022 presidential elections.