State broadcaster RTBF reported that a car forced its way into the site “before exploding a bomb” about 2 AM (0430 IST). No source for the information was given.
RTBF said no one was injured but that damage at the site is significant.
Police have deployed in force and sealed off the area.
The institute assists and advises Belgium’s justice authorities in carrying out their inquiries.
Belgium has been on high alert since a March 22 attack on the Brussels airport and subway killed 32 people.