A monthlong amnesty offered by Saudi King Fahd (search) to militants who turn themselves in has failed to bring in hardcore militants responsible for the killings of scores of Saudis and foreigners in waves of attacks that began in May 2003.

Saudi officials, however, may have gleaned important information from the militants who have turned themselves in, and the officials stress that they have not let up on the hunt for those who remain at large. The offer ends Friday.

Late Tuesday, Saudi security forces killed two militants and wounded three others in a raid on the residence of Saleh Mohammed al-Aoofi (search), believed to be Al Qaeda's chief in Saudi Arabia, officials said.

One of the dead was on the government's most wanted list, the Saudi Interior Ministry said. The identities of the wounded were not disclosed, but two Arab satellite stations reported al-Aoofi could be among them. So far, 13 militants on the kingdom's list of the 26 most wanted have been killed and two have surrendered.

The raid also led security forces to the head of American hostage Paul M. Johnson Jr. (search), found in a freezer. Johnson, a 49-year-old engineer with Apache helicopter maker Lockheed Martin, was kidnapped and beheaded by militants in Saudi Arabia last month. Only his head was found, the Interior Ministry said, and a search continued for the rest of his body.

The Saudi Interior Ministry, in a statement Thursday, sought to encourage last-minute surrenders under the amnesty, in which the government pledges not to seek the death penalty against militants who turn themselves in. The ministry said those who contacted authorities before the deadline could still benefit from the amnesty even if they were not able to turn themselves in until later.

Since the amnesty was announced on June 23, four wanted men have surrendered to Saudi authorities, including Khaled bin Ouda bin Mohammed al-Harby, a confidant of Al Qaeda chief Usama bin Laden, and 27 others have been repatriated from a number of countries.

Questions are being raised about what kind of impact, if any, the pardon offer has had.

Some say the men who have surrendered are providing valuable information.

"The amount of information that's being gleaned from them is huge, and it's going to put the remaining ones in a corner," said Nawaf Obaid, a national security consultant with close contacts within the Saudi government. "They have no way of knowing how much of their logistics, of their networks, even outside Saudi Arabia, have been compromised by this information."

However, Alex Standish, editor of Jane's Intelligence Digest in London, said the surrenders won't have "an enormous impact."

"The key militants, the senior members of Al Qaeda and the people who are active outside the kingdom, these are people who are not likely to be taken in by any amnesty at all," said Standish. "If you surrender to an amnesty what you're really saying is that the struggle was for nothing."

"The committed militants ... do not hand themselves in when an amnesty is declared unless they have achieved substantially the objectives which they set for themselves," Standish added.

The amnesty offer was made in the name of the ailing King Fahd last month after a series of suicide bombings, gunbattles and kidnappings blamed on Al Qaeda members or sympathizers. The violence has created panic among the 8.8 million-strong foreign community that provides much needed expertise in the oil and defense sectors and constitutes most of the blue collar workers in the kingdom.

Saudi Arabia is not the only country to try a more lenient approach with militants. In Yemen, a religious judge initiated a dialogue with jailed suspected militants that resulted in the release of 246 of them. In Iraq, the government is expected to announce an amnesty soon for some insurgents.

Since the Saudi amnesty offer was made, newspapers have carried appeals from religious figures and family members of some of the wanted men calling on the militants to give themselves up. "Surrender, my son. Time is going fast and this opportunity will not be repeated," Saud Abu-Niyan, father of Abdullah Abu-Niyan, urged his son, according to Okaz daily. Saud Abu-Niyan is on the kingdom's list of 26 most-wanted militants.

Those who have responded to the amnesty offer have had "secondary roles," such as smuggling arms and logistical support, said Abdullah al-Oraifig, an editor at Okaz, which is close to the Interior Ministry.

Obaid, the security consultant, said 27 men extradited to Saudi Arabia from several unnamed countries came forward after they heard about the amnesty.

He said most of the men who surrendered have had some basic training at an Al Qaeda run camp in Afghanistan. He said most of them lived underground and gave themselves up because they have no remaining income or logistical support.

Obaid said the surrenders have had an impact on the pool of potential Al Qaeda recruits.

"Seeing all those people giving themselves up ... has broken their appeal," said Obaid.

Standish, however, said that Saudi Arabia's image has suffered since the Sept. 11 attacks with some accusing it of harboring terrorists. The amnesty was not "going to be much more than a public relations gesture."