Moscow — A doctor who treated the survivors of a hostage raid at a Moscow theatre last week defended the Russian military's use of a sedating gas to knock out the Chechen terrorists, saying Monday that it was the only way to end the crisis without massive loss of life.

The toll among the captives rose to 120 over the weekend when the latest victim, a 60-year-old woman, died of a heart ailment, said Lyubov Zhomova, a spokeswoman for the Moscow health department.

Of 149 former hostages still in the hospital Monday, six are in grave condition, she said.

Heavily armed assailants calling for Russian troops to pull out of Chechnya seized the theatre on Oct. 23 during a performance of a popular musical. An audience of more than 750 people was held captive for 58 hours, until Russian special forces pumped a narcotic gas inside and stormed the theatre.

Most of the hostages who died succumbed to the effects of the gas; two others were killed before the raid. Forty-one terrorists were killed by Russian troops.

While some have questioned the use of the opiate-based gas, Russia has said it was the only way to make sure the attackers did not set off hundreds of kilograms of explosives rigged throughout the theatre.

Leonid Roshal, a doctor who went into the theatre during the siege to treat hostages and deliver medicine, praised President Vladimir Putin on Monday for having the "courage" to make the move — the only one that "gave a chance to save lives."

Dr. Roshal dismissed allegations by some Russian media and experts that many victims died because authorities did not treat them for the effects of the gas quickly enough.

"I don't think that any other country could handle it better," he said at a news conference on Monday, arguing that it was impossible to move so many unconscious people from the theatre faster than it was done — about 90 minutes. A parking lot in front of the theatre was filled with the hostages' cars, making it hard for ambulances to approach the building, he added.

Doctors who were among the hostages agreed that rescuers had done all they could.

"It was difficult to carry even one person out of the hall between the rows of chairs," said Vladislav Ponomaryov, who helped take out the two hostages who were shot.

Most hostages said they noticed the gas being pumped into the hall before losing consciousness, prompting observers to wonder what prevented the attackers from blowing up the building.

Dr. Ponomaryov, from the southern Russian city of Krasnodar, said at least several minutes passed from the moment he first noticed a gas with a "sugary smell" filling the theatre hall until he lost consciousness. At the same time, he remembered hearing shots outside the hall as the Russian commandos rushed into the building.

Dr. Roshal suggested that the attackers who were in charge of detonating the explosives had not received the order to do so from their leader, Movsar Barayev, who was outside the hall when the troops stormed in — an opinion voiced by many Russian commentators.