Al-Qaeda chief threatens 'thousands' of 9/11 attacks
Zawahiri addressed the United States in a video published on YouTube days before the anniverary of the September 11 attacks, suggesting the event was in response to "your crimes against us."
The senior al-Qaeda leader cited Washington's policies towards Arab and Muslim nations, its "occupation" of lands in their countries, and support for their "criminal and corrupt" governments, before warning 9/11 "will be repeated thousands of times".
Zawahiri also urged extremists to unite and urged African Americans to convert to Islam to "save" them from US laws which he said are controlled by "the white majority".
His threats come as the US House of Representatives passed legislation that would allow relatives of victims of the 9/11 attacks to sue Saudi Arabia for compensation – a move the White House has threatened to veto.
On September 11, 2001, the Twin Towers of the World Trade Center were struck by hijacked aircraft, claiming 2,753 lives.
The government of Saudi Arabia, a US ally but also the home nation to 15 of the 19 September 11 hijackers, has worked hard to see the bill defeated.
The 9/11 attacks spawned Washington's so-called war on terror, which initially focused on al-Qaeda and the Taliban, before leading the US to a bloody war with Iraq and later targeting the Islamic State group in the region.