The Police National Security Department launched an operation today and arrested a 51-year-old man for collusion with a foreign country or with external elements to endanger national security.

The man is a former media company editor suspected to be connected to a case detected in June. He is being detained for enquiries.

Investigations are ongoing and Police have not ruled out the possibility of further arrests.

Separately, the department revoked the bail arrangements of a 51-year-old woman and two men, aged 55 and 57, who were arrested in June for the same offence. They are being detained for further investigation.

The department laid charges against the four people and they will be brought to the West Kowloon Magistrates' Courts for mention tomorrow morning.