Taiwan has been holding since last month five people from Hong Kong who fled the Chinese-run city by boat and were picked up by Taiwan's coast guard in the South China Sea, sources familiar with the situation said.

Democratic Taiwan has opened its doors to people from Hong Kong, which has been rocked by anti-government protests and where China has enforced a tough national security law. But Taiwan says anyone who enters must do so legally, though its borders are largely closed due to coronavirus prevention steps.

Five sources said the five people held in detention by Taiwan's coast guard had left by boat from Hong Kong and made it to the Taiwan-controlled Pratas Islands at the northern end of the South China Sea.