An employee at the Aristotle University of Thessaloniki on Monday discovered three bags in a building’s basement filled with a total of 49 firebombs and makeshift explosive devices.

The cache was discovered in the polytechnic building’s basement.

A later inspection by police bomb squad technicians revealed that some of the glass beer bottles used for firebombs (“Molotov cocktails”) were attached to pyrotechnic devices and even butane vials – to maximize their explosive and incendiary capacity. Some of the bottles fielded a written warning of containing gasoline.

A further search of the location turned up hidden materials used for making the makeshift incendiary bombs.

The incident is among the latest involving illegal activity on certain Greek university campuses, mainly in Athens and Thessaloniki, and usually attributed to self-styled anarchist groups and anti-state collectives that often seek refuge on campuses from law enforcement.