Note to Zarqawi, if we go non-conventional, you will know it.

You will know it because the sun will rise in your apartment, ok not the 'real sun' but a micro version of it. A tactical nuke on Tal Afar would not be off the table if we knew Zarqawi was there. But gas? If we were going to take the heat for using a WMD, let's use the right one.

The US military denies an accusation that American and Iraqi forces have used toxic gas during an attack on the Iraqi town of Tal Afar in which up to 200 insurgents have been killed.

The accusation was made in an audiotape by a man believed to be Al Qaeda's leader in Iraq, Abu Musab al-Zarqawi.

The message was posted on a website on Sunday, the fourth anniversary of the September 11, 2001 attacks on New York and Washington.

"Anything the man (Zarqawi) says is probably not true. But for certain, the claim of poison gas is not true," a Pentagon official said.