The US Federal Bureau Investigation (FBI) says a new al-Qaeda video has urged the use of nuclear and chemical weapons against the West.

According to US-based monitoring group SITE, a video encouraging would-be terrorists to develop and detonate weapons of mass destruction in the United States and Europe was posted on a website.

The 39-minute documentary-style video, titled "Nuclear Jihad: The Ultimate Terror," was posted on the al-Ekhlaas forum on May 25, SITE announced in a statement.

Richard Kolko, FBI spokesman, downplayed the video, saying there was no evidence of a direct threat or that the group had obtained weapons of mass destruction.

He did say the FBI had sent an alert to US law enforcement agencies about the video. "We got information the tape was coming," said Kolko. "We sent out an alert to law enforcement to let them know the tape was coming."

The latest video, purportedly released by al-Qaeda, has not been authenticated.

The Bush administration invaded Afghanistan in 2001 following the September 11 attacks on the World Trade Center in New York, never managing to capture al-Qaeda leader Osama Bin Laden -- allegedly the mastermind of the attacks.

The US-led war on Afghanistan has claimed a large number of civilian lives.

AO/JG/BGH