Nine Chinese coronavirus patients died at a hospital in Russia on Monday due to a disrupted oxygen supply after an underground pipeline supplying the facility with oxygen ruptured for unknown reasons, local government officials said.

The incident occurred at the Republican Clinical Hospital of Emergency Medicine in Vladikavkaz on August 9. Vladikavkaz is the capital city of North Ossetia-Alania, which is a republic, or federal subject, of Russia in the North Caucasus.

“There was an accident at the oxygen station, interruptions in oxygen supply, in fact, there was a rupture of the oxygen pipe from the tank, which is underground, and the supply was stopped,” Sergei Menyailo, acting head of North Ossetia-Alania, told reporters Monday.

“Unfortunately, we have losses. I express my deep condolences to the families of the victims,” he added.

North Ossetia-Alania’s Ministry of Health said there were “71 people in the intensive care units of the hospital at the time of the accident, 13 of them on the [oxygen] ventilation system. As a result of a short-term stoppage of oxygen supply, 9 people died.”

The North Ossetia-Alania town of Mozdok, located 60 miles north of Vladikavkaz, is supplying the hospital with supplemental oxygen supplies, according to the Russian state-owned RIA Novosti.

“Medical staff has started to connect the patients who are on ventilators to oxygen tanks. Oxygen tanks have started to arrive,” Menyailo said on Monday evening local time.

Government and law enforcement officials in North Ossetia-Alania are currently investigating the incident to determine the pipeline rupture’s cause.

Three people died at a hospital in the Russian city of Ryazan, located southeast of Moscow, in June after a faulty ventilator sparked a fire inside a coronavirus ward.

“Several people also died in May 2020 in fires at hospitals in Moscow and St. Petersburg, with faulty ventilators likewise believed to have sparked the blazes,” Radio Free Europe/Radio Liberty recalled Monday.

One person died in a May 9, 2020, fire at a Moscow hospital, which was treating coronavirus patients at the time. A May 12, 2020 fire at a hospital in St. Petersburg killed five coronavirus patients attached to ventilators.

TOPSHOT – Emergencies personnel work at the site of a fire at the Saint George hospital in Saint Petersburg on May 12, 2020. – A fire at a hospital in Russia’s second city Saint Petersburg on May 12 killed five coronavirus patients who had been attached to ventilators, officials and news agencies said. (Photo by Olga MALTSEVA / AFP) (Photo by OLGA MALTSEVA/AFP via Getty Images)

In a similar incident, an oxygen tank exploded at a hospital treating coronavirus patients in Baghdad, Iraq in April, causing a fire that killed 82 people.

“Among the dead were at least 28 patients on ventilators,” a spokesman for Iraq’s independent Human Rights Commission, Ali al-Bayati, wrote in a Twitter statement on April 25.