Nuri al-Maliki announced the killing of Jordanian-born Abu Musab al-Zarqawi, the head of an organisation known as al-Qaeda in Mesopotamia, at a media conference broadcast by Iraqi state and international media organisations live on Thursday.

An Iraqi state TV report said al-Zarqawi was killed south of Baghdad.

The US military said it would have no comment until after the Iraqi prime minister had spoken publicly.

Earlier, al-Maliki adviser Adnan al-Kazimi told The Associated Press that he had heard a report that al-Zarqawi may have been killed late on Wednesday in Baghdad.

But al-Kazimi said he could not confirm the report.

He said al-Maliki was scheduled to shortly give a news conference along with the top US general in Iraq, General George Casey.

Hoshyar Zebari, the Iraqi foreign minister, told AP over the phone that "since al-Zarqawi's latest video tape, there was a serious effort in chasing him and detecting his movement. The location [where Zarqawi appeared in the video tape] was pinpointed".

The Jordanian-born fighter, who is believed to have personally beheaded at least two American hostages, became Iraq's most wanted man.

The US had put a $25 million bounty on al-Zarqawi, the same as on Osama bin Laden.

Campaign

In the past year, al-Zarqawi had moved his campaign beyond Iraq's borders, claiming to have carried out a November 9, 2005, triple bombing against hotels in Amman that killed 60 people, as well as other attacks in Jordan and even a rocket attack from Lebanon into northern Israel.

US forces and their allies had come close to capturing al-Zarqawi several times since his campaign began in mid-2003.

His closest brush may have come in late 2004. Major-General Hussein Kamal, the then deputy interior ministry, said Iraqi security forces caught al-Zarqawi near Falluja but then released him because they did not realise who he was.

In May 2005, web statements by his group said al-Zarqawi had been wounded in fighting with Americans and was being treated in a hospital abroad - raising speculation over a successor. But days later, a statement said al-Zarqawi was fine and had returned to Iraq.

Previous attempts

There was never any independent confirmation of the reports of his wounding.

US forces believe they also just missed capturing al-Zarqawi in a February 20, 2005, raid in which troops closed in on his vehicle west of Baghdad near the Euphrates river. His driver and another associate were captured and al-Zarqawi's computer was seized along with pistols and ammunition.

US soldiers twice launched massive invasions of Falluja. An April 2004 offensive left the city still in fighters' hands, but the October 2004 assault wrested it from them. However, al-Zarqawi - if he was in the city - escaped.