A summer camp focusing on social and political issues to be held for youths from mainland China, Taiwan, Hong Kong and Macau was canceled due to political pressure, the organizer said Friday.

The weeklong "Co-China" summer camp, to be jointly held next month by the Center for Civil Society Studies of the Chinese University of Hong Kong, apparently drew the attention of the authorities, who uttered threats against the organizer, composed of scholars and social movement advocates.

More than 600 participants and speakers were to take part in the annual event.

"We are worried that if we go ahead with the camp, we will cause trouble for applicants, speakers and volunteers in mainland China," a notice posted on the organizer's Facebook page reads.