BESLAN, Russia – As sporadic gunfire and explosions echoed through this provincial Russian town, anger and despair seethed in relatives gathered near a school yesterday where heavily armed terrorists were holding hundreds of children, parents, and teachers hostage for the second straight day.

The anger was directed at Russian authorities, who families said were vastly understating the number of hostages being held in the school here in the province of North Ossetia, not far from war-ravaged Chechnya. And the despair was evident on the tear streaked faces of the relatives, who despite the release of 26 hostages yesterday, held out little hope that the siege would end without further bloodshed.

Aza Ezaeva, who had six relatives among the hostages including her brother’s three grandchildren, feared that no one would be walking out of the school alive.

“There is no way this is going to end well. They are not going to give in to their demands and the hostage takers will not be taken alive,” she said. “No matter what happens, the lives of everyone in Beslan are going to be changed forever. This is not a metropolis like Moscow; this is a small city. Everyone here has family or friends inside that school; all of us are affected.”

The exact number of hostages being held in the school became an issue of heated debate yesterday on the streets in this city of about 30,000. While authorities said that about 350 hostages were inside the school, families accused officials of trying to diminish the scale of the crisis.

Angry crowds gathered around officials when they gave periodic updates on the siege, with some screaming in choked voices that authorities were lying and that nearly 1,000 hostages were actually being held.

“It’s a terrible lie,” said Fatima, 51, who refused to provide her last name. “My son, my grandson, and my daughter are inside with hundreds of other children and they won’t tell us the truth.”

Families said the school normally has nearly 900 students, all of whom would have almost certainly been in attendance on Wednesday, which was the first day of classes after summer holidays. They also pointed out that mothers traditionally attend the first day of school with their children, often bringing preschool-age siblings along.

“It’s a matter of simple arithmetic, just add it up,” said a man who held a sign reading “Putin: There are at least 800 hostages,” and would not provide his name. “There are 11 grades and each grade has three to four classes of about 30 people. How can they be saying there are so few hostages?”

In the first positive news since the siege began, Lev Dzugaev, an aide to the president of the North Ossetia region, told families yesterday that 26 women and children of various ages had been released. He said especially young children were among those released.

Relatives burst into tears at the news and pressed Mr. Dzugaev for names, but he refused to provide any. Mr. Dzugaev said the releases came after mediation by Ruslan Aushev, a former president of neighboring Ingushetia and a well-respected politician in the North Caucasus. “This is our first success and we will develop this success during our contacts with the people who took the hostages,” he said. “We are asking people to give us time so that we can take part in negotiations.”

The releases came amid increasing tension in the area, as automatic gunfire and loud explosions emanated from near the school throughout the day.

“Any time there is any attempt to approach the school, they open fire on us,” Mr. Dzugaev said earlier in the day. Officials said terrorists in the school fired a rocket-propelled grenade at two cars that had driven too close to the building in the early evening. A gutted and blackened car could be seen about 300 feet from the school.

Shortly after that attack, what sounded like artillery fire could be heard coming from the northwest area of town, far from the school. Witnesses reported seeing heavy tanks rolling into town, but authorities would not confirm the source of the sounds. Soldiers said the army was firing chemicals into the air in order to prevent a predicted hailstorm.

In his first statements on the crisis, President Putin called the seizure “horrifying” and vowed to do all he could to save the hostages. “Our main task is to save the life and health of those who have ended up as hostages,” Mr. Putin said in nationally televised comments. “All the actions of our forces…will be devoted to solving this task.”

Authorities stressed yesterday that they are pursuing negotiations with the terrorists. “There is no question at the moment of opting for force. There will be a lengthy and tense process of negotiation,” said the head of the Federal Security Service, or FSB, in North Ossetia, Valery Andreyev.

Mr. Dzugaev said that it was still not entirely clear what the hostage-takers were demanding, though some news agencies reported that they were seeking the release of fighters captured by authorities in Ingushetia during a raid in June. Mr. Dzugaev said the hostage takers were made up of both Chechen and Ingush terrorists.

Separatist rebels have been fighting Russian forces in Chechnya since 1999 and this raid bears all the hallmarks of one of their operations. The raid came a day after a suspected Chechen suicide bomber blew herself up outside a Moscow subway station, killing 10, and a little more than a week after 90 people died in twin plane crashes authorities have blamed on terrorism.

Authorities said the attackers stormed the building in the early morning, were heavily armed, and included some strapped with explosives. They said the terrorists have set explosives inside the school in order to prevent a rescue operation.

Officials said 16 people were killed when the school was stormed and 13 others wounded, though casualty reports have been unclear. At least 15 people managed to escape from the building, Mr. Dzugaev said.

The number of attackers involved is also unclear. Some officials have said 15-20 terrorists were involved, while others have said up to 40 took part in the attack. Mr. Dzugaev said the hostages were herded into the school’s gymnasium and were being guarded by at least two women strapped with explosives. There was no confirmation of widely circulated reports that the male hostages had been taken into a separate area and shot dead.

News agencies reported yesterday that the attackers had threatened that if police intervened, they would kill 50 hostages for every terrorist killed and 20 hostages for every one injured.

Nothing was known about the food and sanitary conditions inside the school, and officials said offers to deliver food and water had been refused.

Families feared authorities would have no choice but to storm the building, as they did during the Moscow theater hostage-taking in 2002.That siege was ended after an unidentified knockout gas was used to incapacitate the hostage-takers, but the gas also led to almost all of the 129 hostage deaths.