A new round of confidential documents about to be released by the whistle-blowing WikiLeaks organization had officials and analysts around the world on edge Friday as reports spread about the trove’s contents. The documents are said to include proof of a reciprocal double-cross by both the United States and Turkey in aiding terrorist organizations.

Reports speculate that the leaked diplomatic cables will show that Washington aided the outlawed Kurdistan Workers’ Party, or PKK, and that Turkey helped al-Qaeda in Iraq. Anxiety mounted Friday as the United States contacted its allies through its embassies in an attempt to brace for the release of what could amount to millions of documents.

U.S. officials briefed counterparts in Ankara about some documents WikiLeaks will publish that relate to Turkey, Turkish Foreign Ministry officials stated on Friday.

WikiLeaks has not revealed what will be contained in its forthcoming release, saying only that there would be “seven times” as many secret documents as the 400,000 it posted in the “Iraq War Logs,” released in late October.

The Turkish Foreign Ministry on Friday rejected allegations that Turkey has supported al-Qaeda, and the United States similarly denied that it has supported the PKK, which is listed as a terrorist organization by both Turkey and the United States, Hurriyet Daily News reported.