'Hundreds more' in Russian siege
26 women, children released
Officials hope for more progress after militants release 26 hostages.
Tense standoff at the primary school. CNN's Ryan Chilcote reports
Chechen rebels are blamed for dozens of attacks in recent years.
BESLAN, Russia (CNN) -- Russian authorities now believe there may be hundreds more children, parents and teachers being held hostage at a school in southern Russia than originally thought, CNN Correspondent Ryan Chilcote says.
The revised figure comes after tense negotiations with the hostage-takers saw 26 women and children -- some of them infants -- released from the school Thursday. Security forces in military fatigues carried the children to safety.
Chilcote, reporting from the scene Friday, said one freed hostage says more than a thousand people are inside the school.
The earlier estimate of those being held hostage by armed attackers was 350.
But as the siege enters its third day, authorities believe the figure may be hundreds more than that.
Chilcote said a figure of 1,000 to 1,200 people was also consistent with what relatives waiting outside the school have told him.
Earlier, two loud explosions jolted the area. Authorities said the explosions were caused by grenades fired from hand-held launchers from inside the school.
Authorities said negotiators contacted the attackers via cell phone and the hostage-takers said they fired because they claimed there was troop movement near the building.
Chilcote was reporting live, describing the first explosion when the second blast went off.
"There's been another large explosion," said Chilcote, who was several hundred meters away when the blasts occurred. "The situation has turned chaotic here."
Sporadic small arms fire occurred throughout the day, but there had been no shots for several hours before the blasts, which went off around 12:30 a.m. on Friday (2130 GMT Thursday).
The standoff, which began with the armed attackers raiding the school on the first day of classes Wednesday, is now entering its third day.
Ringing the school are Russian troops, tanks and armored vehicles, beyond which are hundreds of frantic relatives and friends of those trapped inside the building.
The attackers have threatened to kill the children if an assault is launched.
"Our most important task in the current situation is, of course, to save the lives and health of those who were taken hostage," Russian President Vladimir Putin said Thursday.
Leading the talks was the former president of Ingushetia, Ruslan Aushev, who has entered the school and met face-to-face with the captors. Ingushetia is a Russian republic bordering Chechnya.
"The freeing of 26 is a big victory, but if you look at the whole picture, it is just a drop, there's still a lot of work to be done," said negotiator and pediatrician Leonid Roshal, one of the people listed by the hostage-takers as someone with whom they would talk.
Authorities said the women in the group gave them a description of what was happening inside: Most of the hostages were being held in the gymnasium and the women and children had been separated from the male hostages.
Authorities said women have been rationing the very limited amount of food in the school to the children, while the school's principal has been trying to keep the children's spirits up.
The children who attend the school range in age from 7 to 17, but infants who were with their mothers are also among those being held captive.
Roshal said he has been negotiating with a man by the name of Shai Khu, who has described himself as the group's press attache.
"Unfortunately, they have again refused to receive medicines, food and water for the children," Roshal said. "He calls himself a warrior. I told him warriors don't behave like this."
Roshal was also involved in negotiations with Chechens who seized a Moscow theater in the middle of a performance in October 2002, holding more than 700 people hostage.
Some of the relatives waiting outside the school have been there since the start of the siege, and have vowed not to eat or drink until their loved ones are released.
One mother whose two young sons are inside the school said she hoped there would be no military operation to try to rescue the hostages.
"Our children must be released. The soldiers must not storm the school, they must settle this peacefully, they must agree to anything to solve this, no price is too high," she told one reporter, her face ashen.
One of the requests made of the attackers is that the families of those killed in the initial assault on the school be allowed to remove the bodies of their loved ones from in front of the building.
Authorities said there are seven bodies. Ten others were wounded in the taking of the 11-grade primary school around 9 a.m. Wednesday.
Officials now believe there are between 15 and 20 armed assailants, at least two of whom are women. Some are reported to be wearing explosives-packed belts.
Earlier, the hostage-takers apparently fired on a car outside the school, setting it on fire, officials at the scene said.
The raid was reminiscent of the siege of the Moscow theater, when Chechen rebels threatened to kill the hostages and demanded an end to the war in Chechnya.
Many of those attackers were women, with explosives belts strapped to their body, while the men were armed with pistols and rifles. Two massive bombs had also been placed in the theater.
That standoff ended when Russian forces piped in poison gas into the theater to knock out everyone inside, but more than 120 of the hostages and 41 of the attackers were killed, most of them from the gas because authorities did not have enough antidote on hand to offset the symptoms.
The current hostage standoff follows a bloody week in Russia, in which a female suicide bomber Tuesday killed nine people outside a Moscow subway station and two airliners were downed by two suspected Chechen female suicide bombers on August 24, killing all 89 people aboard the planes.
Russian officials have said the new wave of attacks is an attempt at revenge for last weekend's elections in Chechnya in which a Kremlin-backed candidate won the presidency.
Beslan is 30 kilometers (19 miles) north of Vladikavkaz in southern Russia, which borders the troubled Russian republic of Chechnya.