Washington - US officials are scrambling to identify the source of the leak of classified documents containing sensitive information on topics ranging from Ukraine's air defenses to Israel's Mossad spy agency.
The sensitive documents cover a wide range of topics, including the war in Ukraine, China, the Middle East, and Africa, leading some experts to believe that an American may be responsible for the leak.
While officials are still investigating the matter, some have not ruled out the possibility that pro-Russian elements could have been involved in the leak, which is considered one of the most serious security breaches since the 2013 WikiLeaks scandal.
More than 50 documents labelled "Secret" and "Top Secret" first appeared on social media websites such as Discord and 4Chan last month, with their existence first reported by the New York Times on Friday.
Reuters reported they have not independently verified the authenticity of the documents, some of them appear to have been altered, and at least one is marked as unclassified but includes top-secret information. Some documents are marked "NOFORN," indicating that they cannot be released to foreign nationals.
Two US officials however suggested that the documents may have been doctored to mislead investigators or disseminate false information that could harm US security interests.
The Pentagon is currently reviewing the validity of the documents, which appear to contain sensitive and highly classified material. The issue has been referred to the Department of Justice, which has opened a criminal investigation.
Watching allies?
One of the leaked documents outlines how Ukraine's S-300 air defense systems could be depleted by May 2 at the current usage rate, which could be of use to Russian forces. Ukraine's president and top security officials have reportedly met to discuss ways to prevent further leaks.
Another one marked "Top Secret," is a CIA Intel update from March 1, which alleges that Israel's Mossad intelligence agency was encouraging protests against Israeli Prime Minister Benjamin Netanyahu's plans to tighten controls on the Supreme Court.
The document suggests that the US learned this information through signals intelligence, implying that the US has been spying on its ally in the Middle East.
In response to the allegation, Netanyahu's office released a statement on Sunday, describing it as "mendacious and without any foundation whatsoever."
Another leaked document discussed internal discussions among senior officials in South Korea regarding US pressure on Seoul to supply weapons to Ukraine. The document also highlighted South Korea's policy of not providing such aid.
In response to the leak, the office of South Korean President Yoon Suk Yeol stated that verifying the authenticity of the documents is a top priority. Once details are confirmed, the government plans to request that the US take "appropriate" steps.
Yoon's office also warned that the possibility of the documents being fabricated or manipulated by third parties cannot be ruled out, and any attempt to disrupt the alliance between the US and South Korea would have serious repercussions.
Some lawmakers from South Korea's main opposition Democratic Party expressed "strong regret" over the allegations of spying, calling it a clear violation of national sovereignty and a significant security failure of the Yoon administration. They have called for a thorough investigation and urged that similar incidents do not happen again.
The Pentagon has not commented on the specifics of any individual documents, including those related to the alleged surveillance of US allies.