Pakistani officials said Tuesday they know the identities of Daniel Pearl's kidnappers, and they now are closing in on the men who abducted the Wall Street Journal reporter. Officials also said they had detained two or three men suspected of e-mailing pictures of Pearl in captivity.

The Reuters news agency reported that Pakistani police had detained two people suspected of sending the e-mails; the Associated Press said three men — identified as Suleiman, Fawad and Adeel — had reportedly been detained.

"We have raided two different places in Karachi during the late evening and are interrogating the two detained persons," Karachi police chief Tariq Jamil told Reuters.

Mukhtar Ahmed Sheikh, in charge of police here in Sindh province, refused to say who was behind the kidnapping, but said:

"The fact is we know who has done it and we are very close to resolving the case.

"There are questions which, if I answer, could affect the case." he said. "But it is enough to say that we might conclude the whole thing very soon, sooner than you think."

Sheikh said he believed Pearl was still alive, and added, "there are so many things I cannot talk about."

However, another senior government official, speaking on condition of anonymity, said the United States believes the mastermind was Sheik Omar Saeed, one of three men freed by India on Dec. 31, 1999 to end a hijacking of an Indian Airlines flight to Kandahar, Afghanistan.

Pearl, 38, was last seen Jan. 23 on his way to meet a Muslim fundamentalist contact at a Karachi restaurant.

A pair of e-mails sent last week are believed to be the only genuine communications from his kidnappers.

In the capital of Islamabad, U.S. Deputy Treasury Secretary Kenneth Dam told reporters that Pakistan was conducting a "vigorous" investigation into the kidnapping, which threatens to cloud President Pervez Musharraf's visit to Washington next week.

Sheikh said Pakistani investigators, aided by the FBI, have been working around the clock to break the case.

He said the kidnapping had "compromised our entire efforts" to attract international investors and clean up Pakistan's image as a dangerous country.

Pearl, the Journal's South Asian correspondent, had been seeking an interview with a Muslim cleric, Sheik Mubarak Ali Shah Gilani. Gilani has been arrested but claims no knowledge of the kidnapping.

Although investigators have not ruled out criminal gangs, their suspicion has focused on the Islamic extremist Harkat ul-Mujahedeen, or Movement of Holy War, and Jaish-e-Mohammed, or Army of Muhammad. Both have been declared terrorist organizations by the United States and have been banned by the Pakistani government.

One of the key suspects is a Harkat ul-Mujahedeen member known as Arif. Police have identified him as Mohammed Hashim Qadeer. He is believed to have been one of Pearl's contacts.

Before leaving for the restaurant, Pearl met with Jameel Yousuf, head of a citizens-police liaison committee formed years ago to combat kidnappings. Yousuf said that during the meeting, Pearl received two mobile telephone calls from a contact whom he knew as Imtiaz Siddique.

According to Yousuf, Pearl agreed to meet Siddique, which may be an alias, at the Village Restaurant, a popular spot favored by foreigners.

Restaurant manager Sayed Shah Salman told The Associated Press that no one recalled seeing Pearl inside the restaurant that night.

In an open letter late Monday, the Journal's managing editor, Paul Steiger, urged Pearl's captors to make contact. Steiger said direct communication would help end the "great deal of confusion" caused by hoax e-mails from people who claimed to be holding Pearl.

Steiger's letter was addressed to the National Movement for the Restoration of Pakistani Sovereignty, a previously unknown group that claimed in a Jan. 27 e-mail to be holding Pearl.

The e-mail included photographs of Pearl — one with a gun to his head — and demands that Washington return Pakistani prisoners held at the U.S. naval base in Guantanamo Bay, Cuba, for trial in Pakistan. The Bush administration has ruled out any negotiations.

The Associated Press contributed to this report.