TOKYO — YouTube has shut down two more channels broadcasting North Korean content, frustrating researchers who say that the information is crucial for understanding North Korea’s leadership, economy and military, as well as the human rights situation in the country.

YouTube, owned by Google, has blocked the Uriminzokkiri channel for “violating YouTube’s community guidelines” and the Tonpomail channel run by Chongryon, initially for “violating YouTube’s community guidelines” and then because of a “legal complaint.”

YouTube’s community guidelines ban videos that include violent, sexual or harmful content, or breach copyright. Google also asks users to flag content that may violate the law.

The decision to block the channels is “a grave setback to the work of open-source researchers,” said Curtis Melvin, who runs the North Korea Economy Watch blog and works at the U.S.-Korea Institute at Johns Hopkins University.

“These North Korean videos are … indispensable sources of information for us on the outside,” Melvin wrote in an open letter to Google and YouTube.

Researchers use the videos for purposes including tracking Kim Jong Un around the country; identifying new economic, security and military infrastructure; knowing what the North Korean government is telling its own people; and interpreting the messages that North Korea sends to other governments, including that of the United States.

The videos were also useful for corroborating or disproving other information about North Korea, Melvin wrote.

The move “hurts efforts to track activities of interest in a closed country — at the worst possible time,” Joshua Pollack, editor of the Nonproliferation Review, wrote in a long thread on Twitter protesting the decision.

Uriminzokkiri is a propaganda outlet linked to the North Korean regime and publishes text and videos portraying Pyongyang’s views. Its recent posts include a video warning the Trump administration that it should be “keeping its eyes and ears open from now on,” and an interview with the sons of an American soldier who defected to North Korea in 1962.

Uriminzokkiri also runs a website and has Facebook and Twitter pages, all of which are still active.

The Tonpomail channel was run by Chongryon, the association of North Koreans in Japan, and broadcast North Korean state news and other media.

The Stimme Koreas channel was also blocked but was then reinstated, both without explanation.

YouTube’s decision to abruptly close the channels follows its shuttering in December of North Korea’s state television channel.

This was apparently done to avoid breaching U.S. sanctions against the regime. Google was concerned not about the content in the channel but at the prospect of the North Korean government earning money from YouTube through advertising.

YouTube said that the decision to close the Uriminzokkiri and Tonpomail channels was made for legal reasons.

“We love that YouTube is a powerful platform for documenting events and shining light on dark corners around the world, but we must comply with the law,” YouTube spokeswoman Jessica Mason said in a statement. “We disable accounts that repeatedly violate our Community Guidelines or Terms of Service and when we are required by law to do so.”

Whenever someone complains to YouTube that an account may be owned by the North Korean government, the company investigates. If there is reasonable evidence that the channel is directly or indirectly owned by North Korea, YouTube disables it.

The channel could be violating American law even if it wasn’t making money for the regime, according to one person familiar with YouTube’s decision.

An executive order issued by President Barack Obama in 2015 bans American people and companies from providing “financial, material, or technological support for, or goods or services to or in support of, the government of North Korea.”

The United States government had also sanctioned North Korea’s Propaganda and Agitation Department and key officials in it, including Kim Jong Un’s sister, Kim Yo Jong.

But the latest U.N. Security Council resolution against North Korea — passed Monday, after YouTube blocked the channels — froze the assets of “the most important North Korean regime organs,” including the Propaganda and Agitation Department, which the U.S. mission to the United Nations said helps the North Korean regime “keep its people down.”

Analysts who study North Korea took to Twitter to complain about the decision, saying that it would severely hamper their ability to find out information about a country that is already the world's most closed.

After the channels were shut down, Martyn Williams, a journalist who runs the North Korea Tech website and has direct access to North Korean broadcasts, tweeted some photos of "IT successes" that the state media organs had been bragging about.

This was a perfect example of information that researchers need to try to figure out what is happening in North Korea, said Melvin. That includes developments in industries that rely on technology, such as the ballistic missile and nuclear weapons programs.