BEIJING (AP) — China has issued a travel warning for the U.S., saying Chinese visitors have been interrogated, interviewed and subjected to other forms of what it called harassment by U.S. law enforcement agencies.

The warning issued Tuesday urges Chinese citizens and Chinese-funded bodies in the U.S. to step up their safety awareness and preventative measures and respond "appropriately and actively."

The warning comes amid an increasingly bitter trade dispute between the sides and tougher immigration enforcement by the Trump administration.

Also Tuesday, the Ministry of Culture and Tourism issued its own travel alert for the U.S., noting the high frequency of shootings, robberies and theft in the country. Chinese students abroad were also urged Monday to assess the risks involved given tightened visa restrictions.

The alerts are valid until Dec. 31.