After receiving 32,000 videos of the recent protests in Iran, the United States said Thursday that the government there has committed "gross human rights violations" that may have left over a thousand citizens dead and thousands more imprisoned since the unrest began in mid-November.

Iran's government has admitted to only a handful of deaths.

"As the truth is trickling out of Iran, it appears the regime could have murdered over a thousand citizens," including at least a dozen children, said Brian Hook, the State Department's special representative for Iran. At least 7,000 protesters have been detained in prison. But, he said, "we cannot be certain because the regime blocks information."

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Earlier this week, Amnesty International estimated "at least 208" have been killed in the demonstrations, citing information the group has gathered.

The government has been trying to cover up the unrest, which is the worst the country has seen since 2009 when election results were disputed. During the protests, it shut down the internet nationwide — an unprecedented move that left the outside world largely in the dark. Virtually all foreign media, including CBS News, have been banned from traveling to Iran to cover the protests.

Amid the unrest last month, Secretary of State Mike Pompeo called on the Iranian people to "send us their videos, photos and information documenting the regime's crackdown on protesters" so the U.S. can "expose and sanction the abuses."

Hook described one of the videos.

"Without warning, the IRGC [Iranian Revolutionary Guard Corps] opened fire on the protesters, killing several people," he said. "Many of the protesters fled to nearby marshlands to escape. The IRGC tracked them down and surrounded them with machine guns mounted on trucks. They then sprayed the protesters with bullets. Between the rounds of machine gun fire, the screams of the victims can be heard.

"When it was over, the regime loaded the bodies on trucks. We do not yet know where these bodies went," said Hook.

When people tried to recover bodies, Hook said the regime "demanded that the families first pay the cost of bullets that they used," and "in many cases, authorities wouldn't hand over the bodies until the families promised not to conduct public funerals."

The protests, which spanned more than 100 cities, began over a sudden hike in gas prices — apparently 300% in one day. Since President Trump withdrew the U.S. from the 2015 Iran nuclear deal last year, and imposed economic sanctions on the country, the national currency collapsed and many Iranians have seen their savings evaporate as jobs remain scarce.

Hook emphasized, however, that "there are no protests against the United States." He said "all of these protests are directed at a corrupt religious mafia that has been terrorizing its own people for 40 years."

Witnesses of the unrest had said some protesters accused their own government of being "the enemy" and of lying to them "that our enemy is America."

Iranian authorities have condemned the protests and accused the demonstrators of being puppets of its adversaries, chiefly the U.S., Britain, Israel and Saudi Arabia. The Iranian government claims there were armed and well-trained groups among the anti-government protesters, who they say killed some members of the security forces.

Camilla Schick contributed reporting.