BRUSSELS: Two days after bomb attacks at Brussels airport and on a packed metro killed 31 people and injured hundreds, a security guard who worked at a Belgian nuclear plant was murdered and his pass was stolen, Belgian media reported on Saturday.

The French language Derniere Heure (DH) newspaper reported the security guard’s badge was de-activated as soon as it was discovered he had been shot dead in the Charleroi region of Belgium and his badge stolen.

A police spokeswoman said she could not comment because an investigation was ongoing. However prosecutors said on Saturday that the murder of the security guard is a purely criminal affair unrelated to any terrorist threat. In a nation on high alert following this week’s attacks, the report stokes fears about the possibility militants are seeking to get hold of nuclear material or planning to attack a nuclear site.

The Charleroi prosecutor’s office in charge of the case “formally denied” any connection between the murder of Didier Prospero, who was shot dead on Thursday at his home in Froidchapelle and a planned terror attack, the Belga news agency reported, citing the prosecutor. There was no immediate independent confirmation from the prosecutor’s office in Charleroi, about an hour’s drive south of Brussels.

On Thursday, DH had reported the suicide bombers who blew themselves up on Tuesday originally considered targeting a nuclear site, but a series of arrests of suspect militants forced them to speed up their plans and instead switch focus to the Belgian capital.

Late last year, investigators found a video tracking the movements of a man linked to the country’s nuclear industry during a search of a flat as part of investigations into the militant attack on Paris on Nov. 13 that killed 130 people.

The video, lasting several hours, showed footage of the entrance to a home in northern Belgium and the arrival and departure of the director of Belgium’s nuclear research program.

Belga said the prosecutor had also denied media reports that Prospero’s access badge had gone missing.

Prospero, who worked for the G4S security firm, was found dead in his bathroom by his three children when they returned from school. He had been shot with four bullets.

His dog was also killed.

He was in charge of security for a nuclear research center at Fleurus. Media had said he worked at a nuclear power plant.

The case is being handled by criminal investigators and terror specialists are not involved, Belga said.

The media reports follow last year’s discovery by investigators of surveillance footage of an official from a Belgian nuclear plant that was found in the flat of a suspect linked to the Brussels and Paris attacks.