Britain has issued new a travel advisory for China, warning that its nationals may be at risk of arbitrary detention.
It comes after several foreigners were held on various charges including cases involving state secrets and national security
"China's authorities have under certain circumstances detained foreigners citing 'endangering national security'," the British Foreign Office said in its latest advice posted on its website.
"There is also a risk of arbitrary detention, including of British Nationals," it said.
British advice previously contained no reference to the risk of arbitrary detention.
A spokesman for the British embassy in Beijing said the advice had been updated to "clearly and factually reflect recent incidents".
"But the level of our advice has not changed," the spokesman said.
In one of the latest high-profile cases, Cheng Lei, an Australian citizen and anchor on Chinese state television, was detained in August for "carrying out criminal activities endangering China's national security," according to China's foreign ministry.
Her detention follows a period of strained relations between China and Australia.