M By David Holley and Sergei L. Loiko

OSCOW, Oct. 25 – Chechen guerrillas who took over a theater here in mid-performance shot a woman to death, authorities said Thursday, increasing fears for the safety of about 700 remaining hostages.

But in a hopeful sign, seven hostages were released early Friday morning, the Federal Security Service said, without citing any reason. And later, an agency spokesman said the rebels had agreed to free all 75 foreigners held captive.

Embassies were asked to send representatives to meet their citizens, but the hundreds of Russian hostages were not to be freed.

The situation remained tense. Hostages telephoned loved ones and said the guerrillas threatened to blow up the theater if the relatives did not organize a large demonstration Friday against the war in Chechnya.

With the theater cordoned off at a distance of several hundred yards and a few armored vehicles visible on streets leading to it, Russian President Vladimir V. Putin issued a statement saying that the main aim of security forces should be “to release the hostages and ensure their maximum safety.”

Negotiators spoke with the heavily armed rebels, who seized the hostages Wednesday night and have demanded an end to the Russian government’s war on separatists in the southern republic of Chechnya. But the talks brought no visible progress.

Terrified relatives of the captives gathered in the gymnasium of a nearby technical school. Most grimly watched news reports on television, while some quietly sobbed and others told reporters that they believe the captors’ demands should be granted.

“I don’t understand why this simple, understandable and justifiable demand of the terrorists cannot be met,” said Liana Okhapkina, 41, a doctor whose daughter, Zhenya, 19, is among the hostages.

“This war has been going on for eight years,” she said. “It killed thousands of people and what is the result? I don’t need this war. I don’t know anybody who really needs this war. Maybe those who started it. But their children are not among the hostages, so what do they care?”

U.S. Ambassador Alexander Vershbow told reporters that President Bush spoke with Putin and “expressed our condemnation of the terrorist act that is still unfolding here in Moscow, and he offered any support and assistance that the United States could provide.”

“We call upon the terrorists to release all hostages–American, Russian and other nationalities–immediately and without conditions,” Vershbow said.

Three U.S. citizens and a Russian citizen holding U.S. permanent resident status are among the hostages, Vershbow said. British officials reported that a dozen of their citizens were inside.

“I just want to underscore the solidarity of our nation with the Russian people at this difficult time,” Vershbow added. “I don’t think this is in any way going to help the Chechen cause, but only create more outrage toward anyone who tries to use terrorism for political ends.”

Chechens won a degree of autonomy for their republic in the Caucasus region after defeating Russian troops in a 1994-96 war. Russian forces marched back into the republic in 1999 and have battled guerrillas there ever since.

Movsar Barayev, leader of the 30 to 50 guerrillas holding the hostages, rejected the label “terrorist” in an interview with London Sunday Times correspondent Mark Franchetti, who entered the theater Thursday with a Russian negotiating team.

Franchetti told reporters that Barayev had said: “We aren’t terrorists, because terrorists ask for money and planes. All we ask for is to pull out the troops from Chechnya.”

Barayev’s uncle, Arbi, was a warlord who gained notoriety as a kidnapper and trader in Russian captives in Chechnya until he was killed last year.

An Internet site believed linked to the rebels–www.kav kaz.org–posted a statement declaring: “The Chechen moujahedeen have taken over a Moscow theater with 1,000 hostages. The Chechen detachment is led by Movsar Barayev In addition to the moujahedeen, there are also 40 widows of Chechen fighters. The building has been mined. All the participants in the operations are also wearing explosives. …

“Barayev said that those who have attacked Moscow are kamikaze rebels. The only demand is that the war should end and that an immediate withdrawal of occupation troops from Chechnya should begin Barayev also said that the Chechen moujahedeen came to Moscow not to survive, but to die.”

Sergei Ignatchenko, a spokesman for the Federal Security Service, or FSB, a successor of the Soviet-era KGB, said Thursday night that 38 hostages had been released since the takeover began, one was dead and about 700 were still being held, including 30 children and 75 foreigners.

While younger children were released, the hostage-takers refused to free those 14 and older, saying that “in Chechnya, 13-year-olds are mature enough to fight,” Ignatchenko said.

The hostage-takers released the body of the dead woman Thursday afternoon.

“It is a Russian girl, about 20 years of age,” Ignatchenko said. “Doctors said she died of a fatal gunshot wound into the chest 16 to 18 hours ago.” The woman also had broken fingers on one hand, he said.

One of the children inside is epileptic, but “the terrorists refuse to accept medicines, for they are treating the hostages roughly,” Ignatchenko added. He did not provide details, other than to say they “sometimes make them lie on the floor.”

Reporters for the Russian television station NTV later accompanied Red Cross doctors into the theater to deliver medicine. They reported that the hostages had been fed and did not seem panicky.

Two women fled the theater early Thursday evening, Moscow police spokesman Kirill Mazurin said. The hostage-takers fired two rounds from grenade launchers at them as they ran, but missed, he said. Reporters positioned as close to the scene as possible had heard the sound of two explosions. At the nearby school gymnasium, relatives of hostages said they understood the two women had jumped out a window.

Okhapkina, the doctor, said her hostage daughter telephoned Thursday afternoon and told her “the terrorists gave them food and water and allowed them to use the toilet, but they could see how the whole place is mined.”

Galina Artyomova, 58, whose daughter-in-law, Anna, 33, was among the hostages, said the younger woman telephoned her Thursday evening and said: “It’s getting worse and worse. Everything is mined here, so these people are really ready to die. I have no doubt about that, nor does anybody else here. If the storming of the place begins, that will be the end of us. We’ll all be dead in no time.”

Grigory Yavlinsky, leader of the Yabloko party in parliament, entered the theater late Thursday evening to begin another round of negotiations with the hostage-takers.

His press secretary, Yevgeniya Dillendorf, said the party leader was taking proposals to the rebels that he believed could help resolve the situation. Yavlinsky left the building again about midnight and went directly to the nearby security operation headquarters.

It was unclear whether more than one hostage might have died. A man who requested anonymity for himself and his wife, a hostage, said she had telephoned him and said: “I don’t know if I’ll be able to call again, but don’t take everything you hear for granted. Things are much, much worse than you may imagine. They have already killed four people.”

The man said he asked, “Did you see them?” and she replied, “I know.”