MOSCOW – Over 100 people were killed overnight when fireworks set ablaze a middle-class restaurant in the Russian Ural city of Perm, as officials Saturday ruled out the possibility of a terrorist attack.

"As of now, there are 102 dead and 134 injured," a regional emergency situations ministry spokesman in Perm told Agence France-Presse by telephone.

Flames went up in the Lame Horse restaurant as some 230 people, mostly employees and their families, were partying inside to celebrate the establishment's eighth anniversary, local police said as quoted by ITAR-TASS, suggesting that the fire was caused by a fireworks rocket gone wrong.

A police source told RIA Novosti that most victims succumbed to carbon monoxide poisoning in the crush as the panicked crowd rushed to escape.

Officials ruled out the possibility that the tragedy was due to a terrorist act as the FSB security service experts found no trace of explosive devices or other clues that could support the theory.

"The accident was due to a violation of instructions when launching fireworks," the investigative committee's spokesman Vladimir Markin told the Vesti-24 television.

"There is no chance it was a terrorist act, I can say that 100 percent," Markin added.

"There were fireworks launched at the scene, and one hit the plastic ceiling, setting all ablaze. People panicked and succumbed to burns, general crush and gas poisoning," the Perm region's public security minister Igor Orlov was quoted by ITAR-TASS as saying at the scene of the accident.

However, a police source quoted by RIA Novosti said that criminal intent could not be ruled out, with "several details I cannot elaborate on pointing at that version."

The source compared the Perm accident with the 1977 fire at Moscow's titanic Rossiya hotel, which killed 42 people. The Rossiya fire was ruled to be due to negligence, but the version of deliberate arson remained persistent.

A government commission was set up to tackle the tragedy, and two airplanes equipped to transport people with serious burns would be dispatched to Perm, Russian Prime Minister Vladimir Putin's spokesman Dmitry Peskov said as quoted by RIA Novosti.

Russia's Emergency Situations Minister Sergei Shoigu, Interior Minister Rashid Nurgaliyev and Health Minister Tatyana Golikova "are due to fly to Perm shortly to set up help for the injured as well as find out the cause of the tragedy," Peskov added.

Prosecutor General Yuri Chaika vouched to personally oversee the investigation, RIA Novosti reported.

Hospitals in Moscow were getting ready to receive the injured, the health ministry spokesman said as quoted by RIA Novosti, adding assurances that "medical aid will be given as much as required."

A local health ministry official told RIA Novosti that 10 of the worst injured were due to be soon transported "aboard a special airplane to a federal burns treatment center" in Moscow.