Residents heard at least one explosion as the blaze erupted in a north Brussels suburb and Belgian media reported a bomb attack, but investigators said the noise was probably materials going up in flames.
Prosecutors said five people were detained for questioning and released without charge following the incident at about 2am yesterday in Neder-Over-Heembeek. Nobody was injured.
“It’s probably not terrorism. It’s a criminal act,” said Ine Van Wymersch, a spokeswoman for the Brussels prosecutor’s office.
“I cannot confirm that there was any bomb.”
The forensic facility assists Belgium’s justice authorities in carrying out their investigations and the lab contains DNA samples found at crime scenes.
“The location was not chosen randomly,” said Van Wymersch, adding that the lab contains sensitive information being used in ongoing investigations.
The fire and damage hampered the efforts of investigators to enter the scene, and she said it would take some time to establish exactly what had been destroyed.
“The laboratory does thousands of analyses each year, so we don’t know what damage has been done yet,” said Van Wymersch. “It is obvious that several individuals would have an interest in making elements in their justice file disappear.”
Belgium has been on high alert since suicide bombings at the Brussels airport and subway killed 32 people in March, and security forces remain on standby for an.
Prime minister Charles Michel announced plans to ease the load on the security services at the weekend.
They include creating a new force to protect key buildings and using more private security firms for concerts or sports events.