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Venezuela's oil minister, Rafael Ramirez, announced Sept. 9 that the investigation into the cause of the deadly blast at the state-run Amuay Refinery, which killed 42 people, has concluded that the explosion was the result of sabotage, the Washington Post reported.

Ramirez explained that a gas leak at the refinery was deliberately triggered by loosening the bolts on a pump. Although he did not specify whether the authorities had any suspects in mind, he said he did not believe employees at the largest refinery in the country had anything to do with the sabotage. Meanwhile, Venezuela's president, Nicolas Maduro, claimed that the explosion was caused by political opponents but did not provide any evidence.

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Damages from the explosion that occurred on August 25, 2012, were estimated to exceed $1.1 billion, Ramirez told reporters at a press conference. Firefighters spent four days trying to put out the fire and the refinery had to work at restricted capacity for many months after the incident. Apart from the 42 casualties, five more people were declared missing after the explosion, the Washington Post said.

Preliminary investigative reports released shortly after the blast revealed that the refinery had been having maintenance issues, leading to numerous minor incidents prior to the August explosion. The report, obtained by the Associated Press, cited 222 accidents that took place at the refinery in 2011, including 100 fires caused by problems with pipes.