The secretive Task Force 121, charged with finding Osama bin Laden, is now actively hunting for suspected terror leader Abu Musab al-Zarqawi as well, says ABC News quoting intelligence sources .

The State Department's Office of Counterterrorism will  soon recommend that the reward for his capture be increased from $10 million to $25 million - the same amount offered for bin Laden, ABC said.

The US believes the 38-year-old Jordanian  was the mastermind behind a string of spectacular suicide bombings in Iraq.

According to the channel, though bin Laden is still perceived as the greatest threat to the United States, US officials now believe Zarqawi has global capability, operating not only in Iraq, but in Saudi Arabia, Syria, Sudan, Iran, Turkey, Kuwait, Pakistan and Afghanistan. 

"He is foreign fighter enemy No. 1," one official was quoted as saying.

The closest the United States has come to capturing Zarqawi was last month, when intelligence analysts determined he was in Fallujah, the heart of the resistance in Iraq.  But Zarqawi escaped, surfacing in Baghdad two weeks later in a most spectacular fashion, ABC said.

He appeared on a videotape via the Internet, in which he  beheaded American civilian Nicholas Berg.  The National Security Agency determined that it was indeed Zarqawi's voice on the tape. Though making the tape was a risky move on Zarqawi's part, many in the intelligence community believe it was a major power play, ABC said.

"It was designed to catapult Zarqawi into the front ranks of those adversaries of the United States that are seen as the most consequential. He is learning from the best - from bin Laden," ABC quoted Bruce Hoffman, acting director of the RAND Center for Middle East Public Policy, as saying.  

Zarqawi is tied to dozens of attacks including the al Qaeda-linked suicide attacks in Istanbul, last year's bombing of the UN headquarters in Baghdad, as well as attacks on the Jordanian Embassy in Baghdad.  An intelligence official told ABC that Zarqawi also had direct ties to the millennium bombing plot of December 1999 to blow up buildings in Jordan, Israel and the United States.

During the 1990s, Zarqawi trained under bin Laden in Afghanistan, but fled to northwestern Iraq after the fall of the Taliban, and worked with poisons for use in potential attacks, ABC said.  During the summer of 2002, he underwent nasal surgery at a Baghdad hospital, but US intelligence officials mistakenly believed he had his leg amputated due to an injury. 

Zarqawi began establishing sleeper cells in Baghdad and acquiring weapons from Iraqi intelligence officials in late 2002, said officials. He reportedly travels freely through the region.