The United Kingdom’s Foreign and Commonwealth Office has updated its North Korea travel advice page on June 10 amidst the recent detention of U.S. citizen Jeffrey Fowle.

The updated version includes an addition to the Local Laws and Customs section, warning UK citizens travelling to North Korea to avoid bringing in any religious materials written in Korean to the country.

“Avoid bringing books or other written material in the Korean language, including anything with religious content,” the travel notice now reads.

According to Kyodo News, Fowle who was in North Korea as part of a tour group, left a bible