Washington -- Chinese officials are in Washington this week to negotiate President Trump's long-promised trade deal amid growing pressure on the Trump administration to sanction China for what Secretary of State Mike Pompeo called the worst human rights abuses since the 1930s.

CBS News Margaret Brennan has obtained a letter sent by a bipartisan group of lawmakers on Wednesday, faulting the administration and urging action to stop mass arrests of Muslims. It cites "mounting global concern regarding China's treatment of its minority populations — human rights abuses that may constitute crimes against humanity."

The letter accuses the Chinese government and Communist Party officials of being "complicit in or directing the ongoing human rights abuses in Xinjiang" a province in western China home to many Muslims, and says while "strong rhetoric" is welcome, "words alone are not enough."

Rounding up religious minorities and putting them in internment camps is something the world long said should never happen again, but the State Department says it is happening in China to more than one million Muslims. So far, the Trump administration has not taken action to stop it.

American Gulchehra Hoja is from Xinjiang Province, home to China's Uighur Muslims. Chinese authorities have taken two dozen of her relatives to internment camps. As a Radio Free Asia reporter in Washington, Gulchehra reports on what is happening back home.

American Gulchehra Hoja CBS News

"My brother [was] detained in 2017, September. After I heard that from my mom, I was asking her can I just talk [about] this issue openly and she was asking me, actually begging me, saying 'I already lost one child, I don't want to lose another one,'" Hoja said. She said she does not know now if her brother or mother are even still alive.

Video posted to Chinese social media has appeared to show the inside of one of these camps. The State Department has said they are designed for mass detention, to "erase religious and ethnic identities."

"They even have cameras in the bathrooms. So 24-7 they [are] watching you" said Hoja, who met with Pompeo last week.

Beijing blames China's Muslim minority for several attacks and says it is rapidly building these facilities to combat terrorism.

On Wednesday, a bipartisan group of lawmakers including Sen. Bob Menendez are calling for sanctions on Chinese officials and cautioning U.S. companies.



"We need to make sure that U.S. companies are not engaged in providing the resources and the wherewithal to allow the Chinese to oppress its own people," Menendez said.

The lawmakers who authored the letter have said they want inspectors to visit the camps and to make sure U.S. companies do not sell surveillance technology that may assist in the abuse.