Prime Minister Vladimir Putin demanded Tuesday that a thorough investigation be conducted into the gas explosion that leveled an Astrakhan apartment block the day before, as the death toll rose to nine with 18 more injured and another 13 still missing, Interfax reported.
"I hope that law enforcement agencies will conduct a thorough investigation and that the cause of this catastrophe shall be discovered in the very near future as soon as an objective investigation will allow," Putin said.
The presidential candidate changed his schedule days before the March 4 election in order to fly to the area and hold a meeting with officials about relief for the injured. He also surveyed the living quarters to which authorities plan to relocate those who lost their homes.
Reports on Monday suggested that the explosion possibly stemmed from a suicide attempt.
"In one apartment [on the third floor], there was a man who periodically brought up thoughts of suicide. He turned on the gas [oven] burners on multiple occasions. And, it seems, before the explosion he carried out this action," said Astrakhan Investigative Committee head Sergei Bobrov, RIA-Novosti reported.
But the arrest on Tuesday of four men — the director and two senior engineers with the region's gas provider, Astrakhangazservis, as well as the director of the managing company of the apartment building — implied that faulty equipment or maintenance may have been behind the explosion.
Various reports suggested that terrorism was being eyed as a possible cause, but investigative journalist and security services expert Andrei Soldatov cautioned that such discussion was pointless unless militant groups laid claim to the disaster.
"So far, I haven't seen any claims by militants that they were behind the attack, so it is not worth speculating on it without any grounds," he told The Moscow Times.
Soldatov, who wrote a book about the FSB in 2010, dismissed suspicions that the security services themselves were responsible, as many claimed after the bombings of four apartment buildings in 1999.
"Specifically for the book, we checked out the information about the 1999 apartment buildings and we didn't find any proof that the FSB was behind it. … So I will not speculate about whether the FSB was behind this," he added.
Those who lost their homes will be compensated with an apartment the same size as their previous one and costing 1 million rubles ($35,000), the local government's spokesman Konstantin Markelov told Interfax.
Residents of Astrakhan started a collection drive for clothes and food for the survivors of the collapse.