BAGHDAD, Iraq (CNN) -- Abu Musab al-Zarqawi was alive on a stretcher when U.S. troops first reached him after an airstrike near Baquba, a U.S. military spokesman said Friday.

Iraq's most wanted terrorist mumbled something indistinguishable and tried to move before he died, U.S. Army Maj. Gen. Bill Caldwell told reporters.

"Zarqawi did survive the airstrike," Caldwell said. "We did in fact see him alive."

Caldwell said he did not know how many minutes al-Zarqawi survived and that he was the only person of the five other people killed by the strike to survive the blast. The dead were three males and three females, including al-Zarqawi, he said.

The terrorist leader tried to move and "mumbled a little something" indistinguishable to troops. Caldwell said.

Al-Zarqawi had not been shot, he said. "No, there was nothing in the report that said he had received any wounds from some kind of weapons system like that."

"They in fact had done some analysis of his body." But Caldwell added he wasn't sure whether it was an autopsy.

On Thursday, Caldwell had reported that al-Zarqawi was dead when U.S. troops arrived.

Caldwell answered questions Friday after he said he had been further briefed on the aftermath of the attack.

"The first people on the scene were the Iraqi police. They had found him and put him into some kind of gurney, stretcher, .... and then American coalition forces arrived immediately thereafter on site," Caldwell said.

"According to the person on the ground, Zarqawi attempted to ... turn away off the stretcher," he said. "Everybody re-secured him back on to the stretcher but he died almost immediately thereafter from the wounds he had received from the airstrike."

Acting on a maze of intelligence and tips, troops had targeted a "safe house" near Baquba in which al-Zarqawi was staying Wednesday evening. An F-16 jet dropped two 500-pound bombs on the house, reducing it to rubble.

President Bush, answering reporters' questions Friday at Camp David, Maryland, said: "Zarqawi's death helps a lot. Zarqawi was [Osama] bin Laden's main advocate outside of some remote parts of the world."

"He was the person who made the declaration that it's just a matter of time for America and other democracies to leave so that they could then develop safe haven from which to launch further attacks," Bush said.

"It's not going to end the war, it's not going to stop the violence but it's going to help a lot."

Caldwell also said that U.S. troops had conducted 39 overnight raids in Iraq, some of which followed up on a "treasure trove" of intelligence found in raids that took place the night before, during the al-Zarqawi attack.

"Last night we conducted an additional 39 operations across Iraq; some directly related to the information we had received, others have not a direct relationship."

Caldwell said troops found caches of "military gear and suicide gear" in the raids, including suicide vests, armament, passports, identification cards, a night observation device and Iraqi army uniforms.

"Zarqawi is dead, but the difficult and necessary mission in Iraq continues," he said. "We can expect the terrorists and insurgents to carry on without him."

At least 37 Iraqis died in Baghdad bombings Thursday, even as the Iraqi parliament ended a stalemate by finally naming key security ministers.

The FBI said there is no evidence that a retaliatory strike is in the works as a result of al-Zarqawi's death, but the agency advised its agents to review ongoing probes and intelligence in the hopes of detecting any possible revenge.

FBI spokesman Richard Kolko said the agency had matched the dead man's fingerprints with al-Zarqawi's prints on file and also would do a DNA analysis. Al Zarqawi's death was confirmed on Islamic Web sites.

Tips and intelligence, authorities said, helped pinpoint al-Zarqawi's whereabouts.

Some of that information may have come from a senior al Qaeda in Iraq figure arrested in Jordan on May 22; more came from Iraqi civilians in and around Baquba; and Special Forces troops tracking al-Zarqawi's spiritual adviser developed still more, with help in at least one instance from those inside al Qaeda in Iraq, authorities said.

Special Forces developed information that the spiritual adviser, Sheik Abd-al-Rahman, would be attending the Wednesday meeting and likely would be with al-Zarqawi, military sources told CNN. Troops were on the ground nearby watching for al-Zarqawi.

Al-Rahman "was brought to our attention by somebody from within the network of Zarqawi's," Caldwell said.

Al-Zarqawi, 39, gained notoriety in February 2003, when then-Secretary of State Colin Powell appeared before the U.N. Security Council to make his case supporting the U.S. invasion of Iraq. Powell pointed to al-Zarqawi, then believed to have been in Baghdad, as evidence that al Qaeda had a presence in Iraq.

Al-Zarqawi was the leader of one of the nation's many insurgent factions. In October 2004, al-Zarqawi pledged his allegiance to al Qaeda founder Osama bin Laden, and renamed his group al Qaeda in Iraq.

Al Qaeda in Iraq was blamed for brazen terrorist attacks, including a 2003 suicide bombing of U.N. headquarters in Baghdad that killed the U.N. envoy to Iraq and 21 others, and the November bombing of three hotels in Amman, Jordan, in which 60 people died.

Al-Zarqawi is believed to have been involved in the abductions and beheadings of several Western hostages. In addition, the United States believes al-Zarqawi had appealed to al Qaeda for help in starting a civil war in Iraq and encouraged sectarian violence.