Seoul: Police are conducting a search at Yeouido Hangang Park in western Seoul after a post online claimed that an explosive device had been planted in the area, sources said Sunday.

According to Yonhap News Agency, the Seoul Seongbuk Police Station received a report around 2:25 a.m. that a threatening post was written on a platform operated by a local broadcaster. The writer claimed people at the park will be hurt unless authorities send 10 million won (US$7,103) in wire payment, sources appraised of the situation said.

Currently, summer festival events are taking place at nine different parks near the river. Police have dispatched special units to the park premises to conduct search operations, while at the same time officers are tracking down the writer of the threatening message.