As many as 20,000 people are feared to have been killed during protests of the Islamic regime in Iran, two sources inside the country confirmed to CBS News this week.

At least 2,500 protesters have been killed since demonstrations began last month, according to the United States-based Human Rights Activists News Agency, which has been accurate with its reports of unrest in Iran in recent years, via NBC News, though the exact total has been difficult to gauge amid widespread internet blackouts in Iran. U.S. President Donald Trump said that Iran stopped killing protesters while addressing reporters at the Oval Office on Wednesday (January 14).

“We’ve been told that the killing in Iran is stopping. It’s stopped. It’s stopping, and there’s no plan for executions,” Trump said via the New York Post. “So I’ve been told that a good authority — we will find out about it. I’m sure if it happens, we’ll all be very upset… but that’s just gotten to me, the information that the killing has stopped, that the executions have stopped, they’re not going to have an execution.”

Trump's comments seem to imply that there will be less pressure for action from the U.S. military, though he had previously launched airstrikes on Iran's nuclear program last June after giving similar comments. The United States began evacuating hundreds of troops from its largest Middle East air base amid turmoil in Iran.

Troops at al-Udeid Air Base are now moving to other facilities and hotels in the Middle East in an effort to get out of harm's way should the U.S. launch an attack on Iran that would be met with retaliation from Tehran, sources with knowledge of the situation confirmed to NBC News. At least 2,500 protesters have been killed since demonstrations began last month, according to the United States-based Human Rights Activists News Agency, which has been accurate with its reports of unrest in Iran in recent years.

Trump publicly threatened to "take very strong action" if Iranian authorities began hanging protesters during an interview with CBS News.

"We will take very strong action. If they do such a thing, we will take very strong action," Trump said.

Iranian Supreme Leader Ali Khamenei warned that the government wouldn't tolerate "mercenaries for foreigners" in a broadcast on national Iranian television via Reuters.

“The Islamic Republic came to power through the blood of hundreds of thousands of honorable people. It will not back down in the face of vandals,” Khamenei said.

The supreme leader's comments followed an internet blackout in Iran amid the ongoing protests. NetBlocks, an internet watchdog, said the blackout and other forms of censorship were imposed by authorities in response to the turmoil. Several videos of the protests have, however, been shared on social media by opposition groups and human rights monitors, which includes protesters calling for Khamenei to be overthrown, as well as the return of Mohammad Reze Shah Pahlavi, the exiled son of Iran's last king.

Pahlavi, who now lives in Virginia, is the heir to Iran's last shah, who was overthrown during the Islamic Revolution in 1979.