Australians travelling to Hong Kong are being warned to “exercise a high degree of caution” when visiting the region as national security laws tighten.

Authorities in Hong Kong now have the power to demand access to personal electronic devices — including passwords — from anyone entering or even transiting through the city’s airport.

Under changes that took effect last month, refusing to surrender a device or disclose its passcode is a criminal offence under Hong Kong’s national security law.

Non‑compliance carries a hefty maximum fine of HK$100,000 ($18,000).

A ban on bringing “alternative smoking products” — including vapes and herbal cigarettes — into Hong Kong takes effect on Thursday, extending to anyone carrying them in public areas or passing through the airport in transit.

The Australian government’s Smartraveller website issued the fresh warning for the destination, explaining the extent of the laws.

“We continue to advise exercise a high degree of caution in Hong Kong,” the alert reads.

“Hong Kong has strict laws on national security that can be interpreted broadly and could be applied to activities that occurred overseas.

“The maximum penalty under Hong Kong’s national security laws is life imprisonment.”

Hong Hong is generally considered a moderately safe place for Australians to travel to, rated the second lowest risk level, at level two.

The website reminded Aussie jet-setters planning to travel to the region in the coming months to be aware of very high pollution and humidity levels between May and October.

From a health perspective, Australians are urged to wash their hands often while visiting as hand, foot and mouth disease is common.