Hong Kong on Tuesday imposed bounties of 1 million Hong Kong dollars ($128,728) on six more pro-democracy campaigners deemed to have violated national security laws, as well as revoking the passports of seven others, in a continuing security squeeze in the financial hub.

Hong Kong's Secretary for Security Chris Tang said the six — all based overseas in countries including Britain and the United States — had engaged in the alleged crimes of incitement to secession and subversion.

The six included U.K.-based commentator Chung Kim-wah, former head of a pro-independence group Tony Chung, and Carmen Lau, a member of the Hong Kong Democracy Council.