ASSOCIATED PRESS Police officers stop motorcyclists outside the lane going to The Wall Street Journal South Asia bureau chief Daniel Pearl's residence in Karachi, Pakistan Wednesday. The Wall Street Journal reported Sunday on its Web site that a group claimed to have seized Pearl.

ISLAMABAD, Pakistan - A group claiming to hold kidnapped Wall Street Journal reporter Daniel Pearl extended the deadline for killing him by one day in an e-mail sent yesterday and warned his abduction is just the beginning.

In Washington, Secretary of State Colin Powell said "we are doing everything we can" to win Pearl's release, but ruled out bending to demands made in previous e-mails for the return of prisoners from the Afghan campaign.

It was impossible to determine whether yesterday's unsigned e-mail, received by Western and Pakistani media, was actually sent by the kidnappers, who abducted the 38-year-old Pearl on Jan. 23 in Karachi.

"We will give you one more day. If America will not meet our demands, we will kill Daniel. Then this cycle will continue and no American journalist could enter Pakistan," the message said.

It warned that unless the demands are met, "the Amrikans (Americans) will get what they deserve. Don't think this is will be the end. It is the beginning and it is a real war on Amrikans."

"Amrikans will get the taste of death and destructions what we had got" in Afghanistan and Pakistan, the e-mail said.

An e-mail over the weekend - the first from those claiming to hold Pearl - demanded Pakistanis captured in fighting in Afghanistan and now held by the U.S. military at Guantanamo Bay, Cuba, be returned here for trial. It said Pearl would be held in the same "inhuman" conditions as the Guantanamo prisoners.

An unsigned e-mail Wednesday set a 24-hour deadline before Pearl would be killed, accusing him of working for the Israeli intelligence agency, the Mossad. It also demanded all American journalists leave Pakistan within three days or become targets.

The latest message gave no reason for the extension and did not specify at what time the countdown began.

A source close to the investigation, speaking on condition of anonymity, said the latest e-mail was sent through the same server as the one received the day before. Yesterday's message did not include photographs of Pearl, as e-mails Wednesday and Sunday did.

Police claim they are pursuing several leads but have refused to give details. Yesterday, a source close to the investigation, speaking on condition of anonymity, said a key suspect known only as Arif was reported dead in southern Punjab province.

The source said police went to Arif's home but was told by his family that he had died a few days ago in Afghanistan. Arif was believed to have been one of Pearl's contacts, the source said.

Powell told reporters that he had spoken with Pakistani President Pervez Musharraf, "and I know that he is doing everything he can."

But Powell ruled out any negotiations with the kidnappers. "The demands that the kidnappers have placed are not demands that we can either deal with or get into a negotiation about," he said.

Pearl, the Journal's South Asian bureau chief based in Bombay, India, was trying to arrange an interview with a Muslim cleric, Mubarak Ali Shah Gilani, when he disappeared. Pakistani police arrested Gilani on Wednesday and carried out raids in several cities, but said they don't know where Pearl is being held.

The first e-mail purporting to be from Pearl's kidnappers, sent Sunday, was signed by the heretofore unknown National Movement for the Restoration of Pakistani Sovereignty. The message included pictures of Pearl with a pistol pointed to his head.

The Wall Street Journal has sent repeated return e-mails denying Pearl is an agent of any government and appealing for his life to be spared. Pearl's pregnant wife and boxing great Muhammad Ali joined those pleas Wednesday.

"Killing Danny will achieve nothing for you," Journal managing editor Paul Steiger wrote in a return message to Wednesday's e-mail. "His murder would be condemned by the entire world, and your group would be viewed as murderers without serious political objectives."

Steiger urged the kidnappers to release Pearl with a "detailed list of the issues and grievances that are important to you" so that he "can articulate them to others."

In an interview with CNN, Pearl's wife, Marianne, appealed to the kidnappers to open a dialogue with her about winning her husband's freedom.

"This is completely wrong, to hold us. It's just creating more misery and that's it. Nothing can come out of there," she said.

Asked if she had a message for her husband, Marianne Pearl said: "I love you." She said she had not slept in days, but was keeping up hope.

Ali, a Muslim, invoked Allah and asked Pearl's captors to show "compassion and kindness" and release him.

"I have not lost Allah's hope in us to show compassion where none exists and to extend mercy in the most difficult of circumstances. We as Muslims must lead by example," the 60-year-old former heavyweight champion said in a statement.

Reporters Without Borders, a non-governmental organization that promotes press freedom, urged five international Islamic religious figures to appeal for Pearl's release. The appeal was made in a letter to King Mohammed IV of Morocco and religious leaders in Egypt, Pakistan, Saudi Arabia and Qatar.

Pearl disappeared after leaving for an appointment at a Karachi restaurant with a contact whom he hoped could arrange an interview with Gilani, head of the small militant Islamic group Tanzimul Fuqra.

Pakistani authorities said Pearl was most likely being held by a known radical Muslim faction - Harkat ul-Mujahedeen - linked to the al-Qaida terrorist organization.