U.S. forces appear to be ramping up their pursuit of Abu Musab al-Zarqawi, considered the most dangerous foreign fighter in Iraq and among the small fraternity of the world's top terrorists.
Officials have said the terror plotter is thought to be moving in and out of Iraq, but they won't provide specifics. U.S. special operations troops who have been used to track down high-priority fugitives such as Saddam Hussein are known to have been moved into the Fallujah area, and U.S. aircraft last week dropped leaflets on the city urging residents to turn in al-Zarqawi.
Attention on al-Zarqawi has increased in recent months as he became a more vocal terror figure, due in part to three recordings released on the Internet, including the video showing the beheading of American Nicholas Berg.
Even this winter, such a profile was uncharacteristic of the 36-year-old al-Zarqawi, previously not known for claiming responsibility for the numerous attacks in which he's believed to have had a hand.
With his public stature in the terror world growing, U.S. officials say al-Zarqawi has joined the ranks of terror leaders that includes Osama bin Laden, his deputy Ayman al-Zawahri and few, if any, others. The State Department and other agencies that handle counterterrorism are considering raising his reward from $10 million to $25 million, putting him on par with the two al-Qaida leaders and Saddam, now jailed.
During al-Zarqawi's years of experience fighting for jihadist causes, U.S. officials say he has developed ties to terror plotters and other Muslim extremists around the world, including individuals in the United States who sympathize with his violent agenda.
Thought of as an ally rather than a member of al-Qaida, al-Zarqawi is not believed to have direct command-and-control links to al-Qaida operatives thought to be in the United States, said an FBI official, speaking on condition of anonymity.
But it is likely, the FBI and other U.S. officials said, that some of these operatives were associated with him at different times.
The officials declined to offer specifics and spoke on the condition they not be identified, citing policies restraining public comments on sensitive investigations.
Al-Zarqawi, whose real name is Ahmad Fadhil al-Khalayleh, joined the jihadist cause in his teens, traveling to Afghanistan to fight alongside the mujahadeen, or holy warriors, battling Soviet forces. The street-smart plotter is thought to have become a student of Islamic literature.
Today, intelligence officials believe al-Zarqawi has cells or links to Muslim extremists worldwide, including countries he has been known to have spent time in: Iraq, Afghanistan, Turkey, Spain, Saudi Arabia, Sudan, Syria, Pakistan and Kuwait.
Secretary of State Colin Powell has also said that al-Zarqawi and his network have plotted against countries including France, Britain, Italy, Germany and Russia.
Until recently, al-Zarqawi was known as the "one-legged terrorist" because U.S. intelligence indicated he received medical treatment and was fitted with an artificial leg in Baghdad in 2002, after fleeing Afghanistan.
However, the belief now is that al-Zarqawi has both legs, even though he is still believed to have traveled to Iraq for treatment for his leg or another injury, a U.S. intelligence official said, speaking on the condition of anonymity.
Al-Zarqawi has been blamed for having a hand in dozens of attacks worldwide. In a letter intercepted in January, al-Zarqawi took credit for 25 attacks in Iraq alone.
On Tuesday, a group claiming to be led by al-Zarqawi -- the Monotheism and Jihad group -- took responsibility for a car bomb attack on a convoy in Baghdad that killed 13, including three General Electric Co. employees.
Last week, the group also claimed responsibility for deadly attacks outside a U.S. military base in Iraq and an ambush that killed four employees of an American security company. U.S. officials are still looking into the claims.
Al-Zarqawi is also blamed for the bombings of the U.N. headquarters in Baghdad in August, a mosque in Najaf, also in August, and the Italian police headquarters in November.
He has also been convicted of several terror plots in Jordan, including the millennium conspiracy there and another against Americans and Israelis that began with the killing of U.S. aid worker Laurence Foley in 2002. Al-Zarqawi has been sentenced to death in abstentia.
On Wednesday, a Jordanian military court convicted 15 men for a terror conspiracy targeting U.S. and Israeli interests in Jordan, as well as Western tourists and top Jordanian intelligence officers. Only one of the men was in custody: the cell's mastermind Ahmad Mahmoud Saleh al-Riyati, who is connected to al-Zarqawi.
Associated Press Writer Curt Anderson contributed to this report.