The three shooting incidents between the police and black people in the US in the past two weeks will boost US public support for Republican presidential candidate Donald Trump, Chinese experts said.

On Sunday morning, an ex-Marine carrying extra ammunition killed three police officers and injured three others in Baton Rouge, Louisiana.

Sunday's shooting is the second incident involving the death of police officers, after a black former US soldier killed five police officers at a peaceful protest on July 7 in Dallas, denouncing the killing of two black men by police in Baton Rouge on July 5 and in St. Paul, Minnesota on July 6.

After the latest incident, Trump tweeted on Sunday that "we are trying to fight ISIS, and now our own people are killing our police. Our country is divided and out of control."

"Since Trump has been advocating a strict immigration policy, he will take this opportunity to rally support from Americans who fear people of various ethnicities in the US," Tao Wenzhao, senior research fellow at the Institute of American Studies of the Chinese Academy of Social Sciences (CASS), told the Global Times. 

Trump said on July 8 the police deaths had shaken "the soul of our nation," adding that such an attack on a police force is "an attack on our country, and an attack on our families."

"The worse the country's social condition is, the more unstable its economy, the better for the Republican Party," said Zhang Guoqing, a research fellow at the Institute of American Studies of CASS.

The shootings have added fuel to tensions between the black community and police in the US, where nationwide protests have mounted since a black teenager was shot dead by a white police officer in Ferguson, Missouri in August 2014, according to Xinhua.

"The conflict between black people and police is a long-existing one in the US. African-Americans can be easily suspected for they have relatively higher crime rates than other groups," Liu Weidong, a researcher at the Institute of American Studies of CASS, told the Global Times.

Liu added that "the police have always been given a lighter punishment when they kill a black than a white person."

"African-Americans are generally less financially stable, which makes it difficult for them to afford lawyers," said Shen Dingli, associate dean of the Institute of International Studies at Fudan University.

An ABC News poll this weekend found that almost two-thirds of those surveyed said race relations were now generally bad - a total reversal of the sentiment detected in the first weeks of President Barack Obama's presidency. A majority said the problem was only getting worse, according to the Guardian.

"The US has laws and rules to eliminate racial discrimination, but the real problem lies in the people's unequal economic background," Shen noted.