DENVER, the United States - Visa restrictions on Chinese students studying in certain areas have come into effect, drawing criticism from US educators.

A computer science major from Beijing, who spoke on the condition of anonymity, told Xinhua he was detained by Homeland Security officials in San Francisco last week for several hours "before they let me go."

The targeting of Chinese students, however, has seen little coverage in the US media.

On Friday, US publication Foreign Policy carried an article, "The US can't afford to demonize China," saying that the complicit US media allows consistent China-bashing based on such themes as "Chinese attempts to undermine intellectual freedom at US universities."

While Department of State officials are unclear about details of the new policy, which came into effect two weeks ago, Chinese graduate students are now limited to one-year visas if they're studying in fields such as robotics, aviation and high-tech manufacturing, according to the only specific information coming out of a subcommittee hearing last month.

"America has just reversed course and defaulted 130 years, playing another prejudiced game against the Chinese," Douglas Hubscher, an educator from Virginia, said.

Hubscher was referring to the 1882 Chinese Exclusion Act signed by then US President Chester Arthur, which prohibited Chinese labor immigration in a concerted political war waged on Chinese nationals. It was repealed in 1943 after Japan attacked both countries.

During those years, many Chinese-Americans were subjected to outrageous acts of prejudice, retired Colorado University history professor John Yee said.

"There's still prejudice against Chinese-Americans in America today," Yee told Xinhua.

According to the Association of International Educators, international students studying in US colleges and universities contributed nearly 37 billion US dollars to the US economy during the 2016-2017 academic year.

"I think they have no idea how large a segment of our society they are affecting, and the economic power they (international students) wield," Hubscher told Xinhua.