Baghdad (AsiaNews/Agencies) - Al Qaeda's leader in Iraq, Abu Musab al-Zarqawi, has declared "all-out war" against Shiite Muslims in Iraq in an audiotape attributed to him and posted on the Internet.

The warning was issued after his militants claimed a devastating series of attacks in Bahgdad, including a massive suicide car bombing in a Shiite area that yesterday killed 112 people, mainly labourers seeking work. This morning at least 15 policemen and five civilians have been killed by a suicide car bomber in southern Baghdad.

"The Al Qaeda Organisation in the Land of Two Rivers is declaring all-out war on the Rafidha [a pejorative term for Shiites], wherever they are in Iraq," the tape says.

"As for the government, servants of the crusaders headed by Ibrahim al-Jaafari, they have declared a war on Sunnis in Tal Afar," the clip added.

The authenticity of the tape could not immediately be verified. but sounded like previous recordings attributed to al-Zarqawi. 

Zarqawi, the one-legged extremist who has a $US25 million price on his head, also urged Sunni Arabs to "wake up from your slumber ... the war to exterminate Sunnis will never end".

The recording also warned all other religious and tribal groups to join his anti-government campaign or also face attacks, saying: "You must choose between the good side and the bad side.

"Any religious group that wants to be safe from the blows of the mujahidin must [disavow] the government of al-Jaafari and its crimes. Otherwise it will suffer the same fate as that of the crusaders," said the tape. 

At the same time, "any tribe ... whose allegiance to the crusaders and their agents is proven will be targeted by the mujahidin in the same way the crusaders are".

Earlier, militants loyal to the Jordanian-born Zarqawi claimed they had carried out the devastating wave of suicide bombings in Baghdad to avenge an offensive by US and Iraqi troops on the northern rebel town of Tal Afar.

The bombings and shootings claimed 150 lives in the capital, making it the bloodiest day of insurgent attacks in the Iraqi capital since the fall of Saddam Hussein.