Islamabad, Pakistan ? An e-mail purportedly sent Wednesday by kidnappers of Wall Street Journal reporter Daniel Pearl threatened to kill him within 24 hours and warned American journalists to leave Pakistan within three days or “be targeted.”

The unsigned e-mail claimed that Pearl, who disappeared Jan. 23 in Karachi, was an agent of the Israeli intelligence service, the Mossad.

“Therefore, we will execute him within 24 hours unless Amreeka (America) fulfills our demands,” the threatening e-mail said.

It accused U.S. journalists of working for intelligence agencies and warned “all Amreekan journalists” to leave Pakistan within three days.

“Anyone remaining after that will be targeted,” it said.

The e-mail was sent to both Western and Pakistani news organizations and contained phrases similar to those in e-mails sent over the weekend by the group claiming to hold Pearl. The group called itself the National Movement for the Restoration of Pakistani Sovereignty.

Pearl’s wife, Marianne, who is pregnant, said in an interview with CNN that she and her husband believed their role as journalists was to create dialogue.

She 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 the two typically worked on stories together. “I’m pregnant, I was sick. Otherwise I would have gone with him,” she said.

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

Wednesday, police apprehended Gilani in the northern city of Rawalpindi and transported him to Karachi, police official Mazoor Mughal said. Police said that they did not know where Pearl was being held but that they carried out raids Wednesday in several Pakistani cities in connection with the investigation.