People protest in Tehran, Iran December 30, 2017 in in this picture obtained from social media. REUTERS.

WASHINGTON (Reuters) - The United States is deeply concerned by reports that Iran has imprisoned thousands of its citizens and tortured or killed some of them in detention, the White House said on Wednesday.

“We will not remain silent as the Iranian dictatorship represses the basic rights of its citizens and will hold Iran’s leaders accountable for any violations,” White House press secretary Sarah Sanders said in a statement.