The e-mail, sent to The Wall Street Journal, CNN and The New York Times, among others, accused correspondent Daniel Pearl of being a spy for Israel. It also warned other U.S. journalists in Pakistan to leave the country within three days. "We have interrogated Mr. D. Pearl and have come to the conclusion that contrary to what we thought earlier, he is not working for the CIA," said the statement, according to CNN, which was accompanied by two photographs of Pearl. "In fact, he is working for Mossad (Israeli intelligence), therefore we will execute him within 24 hours unless America fulfills our demands." It was not immediately clear when the 24-hour deadline would lapse. An earlier e-mail identified the previously unknown group as "The National Movement for the Restoration of Pakistani Sovereignty." The Wall Street Journal denied the claim that Pearl was a spy for Israel, as it has the one made in a previous e-mail that he was spying for the U.S. government. "We have seen the latest communication from the people claiming to Hold Danny Pearl," the newspaper said in a statement. "Mr. Pearl, a U.S. citizen born in the U.S. and a working journalist all of his adult life, is not an agent of any government or agency. He is a reporter for us -- nothing more or less. He cannot affect the policy of the U.S. or Pakistani government. Nor can we." APPEAL FOR DIALOGUE In an interview with CNN, Marianne Pearl said she and her husband went to Pakistan because "we wanted to know more about the people and write about their views. We keep working on that same idea of how are we going to create a dialogue because we know the world is not easy. "I am pregnant. I am going to have a baby. We are trying at our level to create a better world," said Marianne Pearl, who is also a journalist. "It sounds like big words but that's our life. ... I love Pakistan." Pearl, 38, was working on a story about alleged shoe-bomber Richard Reid, who is being detained in the United States ahead of trial on charges he tried to blow up an airliner. Usually the Pearls conduct interviews together, Marianne told CNN That the night Daniel was kidnapped she felt sick and stayed behind. In the Pakistan capital Islamabad, police said they had detained the leader of a radical Islamic group in connection with the kidnapping of Pearl, who went missing in the southern city of Karachi a week ago. Police said they arrested Mubarak Ali Gilani, leader of Jamaat al-Fuqra and considered him a prime suspect in the case. Investigators have said Pearl, who is based in Bombay, India, met Gilani before he disappeared and police have detained and questioned a number of people close to the religious leader and al-Fuqra. WARNING TO U.S. JOURNALISTS Reid allegedly traveled to Pakistan shortly before being caught on a plane in December while trying to detonate his explosive-laden sneakers. The latest e-mail also called on U.S. journalists to leave Pakistan. "We warn all American journalists working in Pakistan that there are many in their ranks spying on Pakistan under the journalist cover, therefore we give all American journalists three days to get out of Pakistan. Anyone remaining after will be targeted."

The New York-based Committee to Protect Journalists repeated its call for Pearl's release. "His kidnappers have gained absolutely nothing by holding him hostage," CPJ executive director Ann Cooper said in a statement. "They will gain absolutely nothing by threatening to kill him. They will also gain nothing by threatening other journalists working in Pakistan." A number of Pakistani and U.S. media organizations received e-mail on Sunday saying Pearl had been kidnapped. It said Pearl, who it claimed worked for the CIA, was being kept in "inhumane" conditions to protest against the treatment of Taliban and al Qaeda prisoners held at a U.S. naval base in Guantanamo Bay, Cuba. The e-mail also contained four photos, including one with Pearl's wrists chained and a pistol pointed at his head. Marianne Pearl said she hasn't slept for six days, but she remained hopeful her husband would be released. "I'm not desperate. If I stop believing in creating this dialogue, then I'd have to stop believing in everything else, so I can't do that. I'm pregnant." Asked what she would say to her husband if she could speak to him now, she smiled and said, "I love you."