US and Iraqi forces said they have shot dead the second-in-command of al-Qaeda in Iraq, dealing what a US commander called Tuesday a serious blow to the militant group at the heart of Iraq's insurgency.

US and Iraqi forces tracked Abu Azzam, said to be the right-hand man of Abu Musab al-Zarqawi, the most wanted man in Iraq, to a high-rise Baghdad apartment building where he was shot on Sunday, US spokesman Lieutenant Colonel Steve Boylan said.

"We got specific information and intelligence that led us to him," Boylan said. "We've been tracking him for a while."

The death suggested progress against the two-year-old insurgency, particularly as the military said Azzam was behind a surge in violence in Baghdad since April that has killed and maimed hundreds. But attacks continued unabated.

But Al-Qaeda in Iraq said Tuesday it was not yet sure if an operative named Abu Azzam died in a clash with US forces in Baghdad, but denied he was the deputy of al-Zarqawi.

"The holy warrior Abu Azzam al-Iraqi is an al-Qaeda soldier who heads one of al- Qaeda's units operating in Baghdad ... it has not been confirmed to us yet if he died," said a statement on an Islamist website often used by al-Qaeda in Iraq.

"A large force of crusaders surrounded the area he lives in using helicopters, and there was a clash between the warrior and the crusaders when they tried to storm his apartment," it added, apparently confirming the incident reported by US forces.

It is uncertain how much intelligence the alleged Azzam's killing will deliver as he died before being questioned. US and Iraqi forces tried to capture him alive but he shot at them, a statement said, and when troops returned fire, he was killed.

An Iraqi government spokesman said he was with other men at the time but it was not clear what happened to them. He said he was unsure how important the death of Azzam, an Iraqi, was.

"Even those members of this network who are arrested know nothing (about the organization) except noms de guerre and symbols," Laith Kubba told Al-Jazeera television.

Azzam commanded day-to-day operations in Baghdad and other cities, while financing attacks and the passage of militants into Iraq from abroad, the US military said.

"In spring 2005, he assumed the position of Emir of Baghdad, where he reportedly directed and controlled all terrorist activity and operations in and around the city," it said.

His alleged death follows the capture or killing of several Zarqawi associates in recent months, including a driver and several junior commanders, that have led US forces to believe they may be closing in on the guerrilla chief himself.

A Jordanian, Zarqawi is allied to Osama bin Laden and his al-Qaeda network. His group has claimed many attacks in Iraq, and has pledged all-out war against Iraq's majority Shi'ite population, a bid to provoke civil war.

The US military was quick to hail the breakthrough.

"By taking Abu Azzam off the street, another close associate of Zarqawi, we have dealt another serious blow to Zarqawi's terrorist organization," said Major General Rick Lynch, chief spokesman for US forces.

But officials have warned of more violence in the run-up to a referendum on a new constitution on Oct. 15, when voters are expected to say "Yes" to a document drawn up by the Shi'ite- and Kurdish-led government over Sunni Arab objections. The Sunni Arab minority forms the bulk of the insurgency.

While the US military was upbeat about Azzam's killing, the capture or death of suspected militant commanders has not always led to a decline in attacks in the past.

Al-Qaeda denies

An internet statement denied on Tuesday reports that the right-hand man of Abu Musab al-Zarqawi, the most wanted militant in Iraq, has been killed by US forces.

The statement, posted in a web site usually used by al-Qaeda in Iraq, said it could not confirm whether Abu Azzam has been shot dead by Iraqi and US forces in the Iraqi capital Baghdad.

Azzam, a financier and religious aide to Zarqawi, was killed in a joint US-Iraqi raid on his hideout in an apartment building on Monday, the US military said Tuesday.

The authenticity of the statement could not be verified.

Al-Qaeda in Iraq, which is linked to Osama bin Laden's al-Qaeda terror network, is one of the most feared militant groups in the country and claims responsibility for many of the deadliest attacks in Iraq.

Zarqawi, a Jordanian-born militant, has a 25-million-dollar bounty on his head by US authorities.

Source: Xinhua/China Daily