There's a massive new leak of confidential spy files from MI6, Mossad and the FSB

Al-Jazeera has obtained hundreds of confidential "spy cables" from some of the world's top intelligence agencies, in what the news channel is calling "the largest intelligence leak since Snowden."

Documents from Britain's MI6 and Israel's Mossad are included, along with the Russian FSB, South African SSA and the Australian ASIO. (No American intelligence agencies appear to be included.) Al-Jazeera is publishing the leaks over the coming days in conjunction with the Guardian, promising that they will provide "an unprecedented insight into operational dealings of the shadowy and highly politicised realm of global espionage."

The documents date from 2006 to December 2014. They will be redacted before publication and their full contents are not yet known, but reportedly include:

• Israel's "true" assessment of Iran's nuclear capabilities.
• An MI6 operation to recruit a North Korean spy.
• "An assassination plot targeting an African union leader."

The source for the documents appears to be a leak in South Africa's SSA agency, including "detailed briefings and internal analyses written by operatives of South Africa's State Security Agency (SSA)", as well as "secret correspondence with the US intelligence agency, the CIA, Britain's MI6, Israel's Mossad, Russia's FSB and Iran's operatives, as well as dozens of other services from Asia to the Middle East and Africa."

Here's Al-Jazeera's trailer for the forthcoming leaks: