Conflicting statements about the alleged leader of al-Qaida in Iraq have appeared on the internet recently after the group announced on Tuesday that al-Zarqawi had been wounded.
But a statement on Friday said: "Our sheikh is in good health and is running the jihad (holy war) himself and has been overseeing the details of operations up to the time this statement was prepared," a group spokesman said in a posting issued on websites.
The authenticity or origin of the websites has not been independently verified.
According to the latest statement, the network of fighters was not experiencing problems.
"Our sheikh has over the past two years established a cohesive leadership and has a deputy and advisers," it said. "Al-Qaida organisation in Iraq is well and cohesive."
On Thursday, an internet statement in the name of al-Qaida Organisation for Holy War in Iraq said the group had named a deputy to fill in for al-Zarqawi, but a later statement attributed to the group spokesman swiftly denied it.
Iraq's Interior Minister said on Thursday he had confirmation al-Zarqawi had been wounded, but the country's prime minister later said there was no firm news.
Washington has offered a $25 million bounty for al-Zarqawi.
Al-Qaida said on Tuesday al-Zarqawi had been wounded "in the path of God" but did not say how, when or where. It urged Muslims to pray for his recovery, and vowed to step up its attacks against US forces and the Iraqi government.
Iraq's government said on Thursday it would pour tens of thousands of Iraqi troops into Baghdad in an unprecedented operation to seal off the city and hunt fighters.
A separate al-Qaida statement posted on a website on Friday said the operation was a plot against Sunni Muslims launched by the Shia-led government because it was failing against the fighters.
Thousands of troops are to be
deployed to stop the attacks
"In order for Sunnis not to be fooled by this plot, we tell them that they are trying to harm the Sunnis, but they will be disappointed," the statement said.
"The soldiers of God and the Sunnis will be victorious."
Meanwhile, the US military announced that a rocket-propelled grenade had killed a US marine in western Iraq.
The marine was assigned to the II Marine Expeditionary Force and killed Thursday in Haditha, 220km (140 miles) northwest of Baghdad, during Operation New Market.
The name of the deceased is being withheld pending next of kin notification. Another marine was reported killed on the opening day of the operation on Wednesday. At least 1653 members of the US military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.