American journalist Daniel Pearl, kidnapped in Pakistan while trying to make contact with Islamic radical groups, was executed on camera by his captors who slit his throat, U.S. and Pakistani officials said on Friday.

Pakistan's president, Pervez Musharraf, who has rallied to the U.S.-led war on terrorism and cracked down on Islamic radicals, denounced the murder as gruesome and ordered an all-out nationwide manhunt for suspects still at large.

President Bush, speaking during a visit to China, called the killing of the 38-year-old Wall Street Journal reporter a "criminal, barbaric" act. Pearl's family said it was a "senseless murder" that had silenced "a gentle soul."

A top Pakistan government official told Reuters authorities learned of the killing of Pearl, abducted in Karachi on January 23, from a videotape of the murder sent to a Pakistani reporter in Karachi Wednesday or Thursday.

Pearl's death was formally announced late Thursday night.

His body has not been found and it is unclear exactly when and where he was executed.

One U.S. official in Washington called the death tape "very gruesome." He provided no details.

But in a account of Pearl's last moments, the Pakistani official, who asked not to be identified, said Pearl's last words uttered on camera before his killing were that he was a Jew and his father was a Jew.

"I have been told that the last words uttered by Pearl in the videotape, immediately before his throat was slit, were 'Yes I am a Jew and my father is a Jew'," the official said.

"Maybe he was forced by his kidnappers to say these words."

Dr. Riffat Hussein, a defense and strategic studies analyst at Islamabad's Quaid-e-Azam University in Islamabad, said the sophistication of the kidnapping pointed to possible involvement of Osama bin Laden's al Qaeda network, chief suspect for the September 11 attacks on the United States.

"If you look at the character of this case -- the methodology that was used, the use of email, and videotape -- it suggests it may have some very significant al-Qaeda links," Hussein said.

A Pakistani source close to the investigation told Reuters the video was short and showed Pearl's throat being cut.

"The scene that apparently confirmed the murder of Pearl was when one person's hand cut the U.S. reporter's neck with a sharp tool," the source, quoting someone who had seen the tape, said.

The source added that the tape showed the hands of two or three other people.

Pearl disappeared in Karachi, Pakistan's largest city, as he tried to contact Islamic radical groups and investigate possible links between alleged shoe bomber Richard Reid and the al Qaeda network of suspected September 11 mastermind Osama bin Laden.

MURDER ON TAPE
The group claiming to hold Pearl, calling itself The National Movement for the Restoration of Pakistani Sovereignty, accused him of being a spy -- first for the CIA, then for Israeli intelligence. It said it was protesting against U.S. treatment of Taliban and al Qaeda prisoners.

Lonnie Kelley, U.S. Public Affairs officer at the U.S. consulate in Karachi, told Reuters "both Pakistan and U.S. investigators have identified the perpetrators behind the crime." Police are already holding some suspects.

They include key suspect Ahmed Omar Saeed Sheikh, a British-born Islamic militant commonly known as Sheikh Omar who has previous links to kidnappings.

"Pearl's murder is outrageous and the United States is determined to bring the perpetrators to justice," Kelley said.

Wall Street Journal Publisher Peter Kann and Managing Editor Paul Steiger said in a statement: We are heartbroken. His murder is an act of barbarism that makes a mockery of everything Danny's kidnappers claimed to believe in.

"Their actions must surely bring shame to all true Pakistani patriots," they said.

PREGNANT WIFE
The Pakistani official said the reporter who received the tape took another 24 hours to convince U.S. authorities they should view the tape.

"According to my information, the videotape was in the possession of a (Karachi-based) Pakistani reporter for 24 hours while he was trying to contact the U.S. consulate to deliver it to them," the official said in an interview with Reuters.

Pearl's family called him "a beloved son, a brother, an uncle, a husband and a father to a child who will never know him." Pearl's wife Mariane, who was in Karachi, is more than six months pregnant with their first child, a son.

Bush said he was deeply saddened by Pearl's death, saying the murder would only hurt the cause of his captors. "All Americans are sad and angry to learn of the murder," Bush told reporters in Beijing, where he is on the final day of a six-day trip to Asia.

"Those who would threaten Americans, those who would engage in criminal, barbaric acts, need to know that these crimes only hurt their cause and only deepen the resolve of the United States of America to rid the world of these agents of terror."

In Islamabad, the Pakistani government vowed every member of the kidnap gang would be hunted down.

"General Musharraf has directed the government of Sindh (the province where Pearl was kidnapped) and other national security agencies to apprehend each and every member of the gang of terrorists linked to this gruesome murder," a statement by the president's office said.

Pearl, the Journal's South Asian bureau chief based in Bombay, India, for the past two years, had been working in Karachi for three weeks when he was kidnapped.

Friends said he was smart, sweet, soft-spoken, self-effacing and unlikely to take unreasonable risks. He also was a talented fiddler, guitarist and classical violinist. One of three children, Pearl's father was an academic and his mother a computer consultant.

Pearl's family said in their statement that "up until a few hours ago we were confident that Danny would return safely, for we believed no human being would be capable of harming such a gentle soul."

Outside the temporary newsroom in New York of The Wall Street Journal, which was displaced after the September 11 suicide hijack attacks in the city, Journal reporters said they had been asked by management not to talk about Pearl.

One unidentified reporter said people inside the newsroom were extremely upset. Another called Pearl's death "a despicable act."

"JUST A REGULAR GUY"
"He was just a regular guy doing his job. He wouldn't hurt a fly. It's just disgusting," the reporter said.

Pearl, a Princeton, New Jersey, native, grew up in the suburbs of Los Angeles and graduated from Stanford University.

U.N. Secretary-General Kofi Annan saluted the courage of Pearl and other journalists around the world. "The crime highlights the enormous dangers encountered by journalists, particularly in areas of conflict and violence," Annan said through his spokesman, Fred Eckhard.

In New York, the Committee to Protect Journalists called Pearl's death "brutal, wanton, and senseless."

Thursday, Fahad Naseem, one of three men accused of involvement in the kidnapping, said Pearl was abducted because he was a Jew working against Islam, according to his lawyer.

Pakistan police in early February arrested Naseem and two other suspects for sending emails to media organizations that showed Pearl in captivity.

The Journal is owned by publisher Dow Jones Co .