Washington (CNN) President Donald Trump on Sunday tweeted another warning to Iranian leaders -- "DO NOT KILL YOUR PROTESTERS" -- as thousands of anti-government protesters gathered in Iran this weekend following Tehran's admittance it mistakenly shot down a Ukrainian passenger jet, killing all 176 people on board.

"To the leaders of Iran - DO NOT KILL YOUR PROTESTERS. Thousands have already been killed or imprisoned by you, and the World is watching," Trump wrote. "More importantly, the USA is watching. Turn your internet back on and let reporters roam free! Stop the killing of your great Iranian people!"

The tweet comes hours after the President voiced his administration's support for the protesters , writing on Twitter that he has "stood" with them since he took office nearly three years ago.

"(A)nd my Administration will continue to stand with you. We are following your protests closely, and are inspired by your courage," he tweeted in both English and Farsi.

In a separate tweet on Saturday, Trump wrote that Iran's government "must allow human rights groups to monitor and report facts from the ground on the ongoing protests by the Iranian people."

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