China has issued two travel alerts to its citizens going to the US, warning them about police harassment and crime.

The warnings come amid an escalating trade war between the world’s two largest economies and other tensions including attacks on each other’s human rights records.

“Recently, shootings, robberies and thefts have occurred frequently in the United States,” Chinese state media reported, citing a statement from the ministry of culture and tourism.

The statement urged Chinese tourists to “fully assess the risk” and “improve their awareness of safety and security”.

In a separate warning, China’s foreign ministry said US law enforcement agencies have repeatedly used methods such as immigration requirements and on-site interviews to “harass” Chinese citizens in the US.

It urged Chinese nationals and Chinese-funded institutions in the US to be cautious and “increase awareness and strengthen preventive measures”.

The warnings come a day after the education ministry said students and academics were facing US visa problems and urged them to assess the “risk” of travelling to the US.

They coincide with the 30th anniversary of a deadly crackdown on student demonstrators in Tiananmen Square. The crackdown has been seen as a turning point for the country, marking the increasing authoritarianism of the Chinese leadership.

Under Xi Jinping, Chinese civil society has come under even more pressure. Dozens of activists have been detained in the lead up to the anniversary and censorship appears to have increased.