Afghan officials said negotiations neared a breakthrough Thursday on final terms of surrender for deposed Taliban leader Mullah Mohammed Omar and 1,500 of his fighters.

U.S. officials were adamant that no deal had been offered to the second most wanted man after Usama bin Laden.

The governor of the southern city of Kandahar, Gul Agha, said Omar, accompanied by about 1,500 Taliban fighters, has been talking with a grand council of tribal leaders. U.S. officials have expressed doubts that Omar planned to give himself up.

If Omar doesn't agree to be arrested, the Baghran region in the mountains north of Kandahar, where he is believed to be hiding, faces possible bombing by U.S.-led warplanes, said Afghan and Pakistani military officials.

Afghan intelligence official Nusrat Ullah said negotiators were working out the final surrender terms for the fighters. "We have received positive response from those tribal chieftains who are sheltering Omar and his associates in Baghran," he told The Associated Press by satellite telephone. "A breakthrough in this regard is expected soon."

Asked about the talks over Omar, Defense Secretary Donald H. Rumsfeld said in Washington that the United States would not approve of any negotiations "which would result in freeing of people who ought not to be freed," including those involved in terrorism or harboring terrorists.

"I know that the interim government is right on the same sheet of music with us, with respect to this. They want the Taliban caught," Rumsfeld said.

Also Thursday, American warplanes struck a "fairly extensive" Al Qaeda compound and training ground near the eastern town of Khost, Gen. Richard Myers said at the Pentagon.

The base "has been a place where the Al Qaeda goes to regroup" and is the same one struck by cruise missiles in 1998 in retaliation for the bombing of U.S. embassies in East Africa, said Myers, chairman of the Joint Chiefs of Staff. He did not comment on casualties or damage from the strike.

Bin Laden, chief suspect in the Sept. 11 terror attacks on the United States, is also indicted in the embassy bombings.

The Kandahar governor said his administration also was negotiating with Abdul Wahid, a prominent pro-Taliban warlord, for the surrender of his weapons. Wahid already has handed over some weaponry, Agha said.

Some Afghan officials have said Wahid's fighters are sheltering Omar, but this has not been confirmed.

Two flatbed 16-wheel trucks hauling large metal boxes of ammunition were seen Thursday arriving in the southern city of Kandahar from the direction of Baghran to be handed over to Agha.

It was not known if the weapons came from Wahid or from other Taliban weapons caches in the area that U.S. Marines have been finding and logging before handing them over to Afghan officials.

In other developments:

— Prime Minister Hamid Karzai has agreed to visit President Bush next month in what will be the first visit by an Afghan leader in almost 40 years, the White House said.

— Pakistan arrested the former Taliban ambassador in Islamabad, Mullah Abdul Salam Zaeef, said Zaeef's nephew, Hamid Ullah. He said he did not know the reason for the arrest of Zaeef, who was the most prominent Taliban spokesman during the U.S. campaign against the militia.

— Myers said the United States is currently holding 248 detainees from Afghanistan either at U.S. bases in the country or on ships.

Afghanistan's new government brought 320 Taliban prisoners to Kabul, the capital, for release. Some of the fighters had spent years locked away by Northern Alliance groups when they controlled only a small percentage of Afghan territory.

Security Ministry officials called it a gesture of national reconciliation and said more releases would follow. It was not known if the prisoners included Al Qaeda fighters.

"We are very pleased with the government," said Abdul Shukur, one of the newly freed prisoners. "God willing, I'm on my way home to see my family."

Most of the freed prisoners, who ranged in age from teen-agers to men in their 50s, appeared to be in good health. They were handed over to village chiefs and tribal elders who pledged to support Karzai's administration.

In the eastern city of Jalalabad on Thursday, more than 800 fighters belonging to Nangarhar province's ruling council began hunting Al Qaeda members, the Pakistan-based Afghan Islamic Press reported.

The hunt started in the Chaparhar area, between Jalalabad and Tora Bora, the last stand of Al Qaeda fighters in eastern Afghanistan. The agency's report said Al Qaeda members may be hiding there.

U.S. Marines operating out of a base in Kandahar's airport have also been searching Taliban and Al Qaeda facilities in the south. During a 29-hour mission that began Monday, Marines found documents, guns and other items that could be useful, U.S. defense officials said Wednesday.

After a camp 60 miles outside Kandahar was searched by the Americans, journalists who went to the warren of caves saw graded terrorist exams, a book by bin Laden declaring an anti-American jihad and instructions on assassinations and bomb-making.

About 200 Marines from the Kandahar airport bases also searched a 14-building compound west of the city, trying to locate former Taliban rulers who went underground after the fall of Kandahar, one of their last strongholds.