Suspects are in custody after authorities in Paris found an improvised explosive device near the Paris Saint Germain soccer stadium.

According to the The Sun, the device, which involved four cylinders covered in gas, was found early Saturday morning just hours before the Paris Saint Germain club was set to take on Bordeaux.

The device was linked to a mobile phone that was rigged to ignite the cylinders. Close to 50,000 spectators were set to descend on the stadium. A source told The Sun that the device was found by a local resident who called police around 4:30 a.m.

Five suspects were arrested at the scene, including one that police said has links to radical Islamist movements. French Interior Minister Gerard Collomb said the suspect was on the FSPRT file, which denotes someone that has been radicalized and is displaying the characteristics of a terrorist.

All of the suspects arrested on Saturday are still in custody but none have been formally charged.

Collomb said the discovery of the bomb showed that France is at an “extremely high” risk of terrorist attacks.

Andy Berg is Executive Editor of Athletic Business.