“Too many questions have been left unanswered,” said Elizabeth Andersen, executive director of Human Rights Watch’s Europe and Central Asia division. “The authorities are silent precisely when information is a matter of life or death.”

Increasing evidence suggests that many hostages died because they were not given basic medical care immediately after their rescue. Television images showed special forces placing on bare concrete unconscious hostages, who were then left utterly unattended. Footage indicated that no doctors were available outside the theater at that time.

Russian authorities continue to withhold vital information about the gas, even though it is of key importance to medical doctors who are still treating hostages—some of whom are still in grave condition—and to survivors, who may face long-term health consequences.

According to reliable sources who spoke to Human Rights Watch, doctors from several humanitarian organizations who were in the theater’s immediate vicinity sought access to the released hostages but were denied by security officials. When doctors finally did see the hostages, in ambulances or hospitals, medical personnel were unable to prescribe appropriate treatment, as officials had not informed them of the substance that was used.

“The Russian government should have made sure that medical doctors with knowledge of the exact gas used and equipped with sufficient quantities of antidote were at the theater at the time of the operation,” said Andersen. “The lack of an appropriate plan for this aspect of the operation is an inexcusable violation of the right to life.”

International law does not prohibit the use of potentially lethal force in operations to liberate hostages, but it requires that such force be “absolutely necessary” and that all precautions be taken in both the planning and execution of such operations to minimize the loss of civilian life.

Human Rights Watch calls on Russia to establish an independent commission of inquiry to investigate the lack of medical care in the aftermath of the raid. The commission should also examine other key concerns:

• The government has refused to clarify which gas it used during the operation. The commission should identify the gas and investigate whether the use of this gas was permitted under the Convention on Chemical Weapons.

• The commission should investigate the circumstances of all deaths in relation to this incident and determine whether any were extrajudicial executions. Media reports and television footage suggest that some of the estimated fifty hostage-takers who died in the operation were unconscious when special forces shot them.

• The commission should also ensure that proper forensic autopsies are performed on victims in a timely manner, before valuable forensic evidence is lost.