Inter Milan manager Antonio Conte has been sent an anonymous letter which contained a bullet and a number of threats. 

According to Italian publication Corriere della Sera, the envelope has left a cloud over the club. 

Security has been stepped up following the delivery, with Conte's house and Inter's training ground now under police protection. 

An investigation has been opened and police will be testing the envelope for fingerprints in an attempt to discover the identity of the sender and the motive they had. 

Per the Daily Mail, video surveillance systems on the road of Conte's home and at Milan's training ground will be analysed in case a secondary delivery is made.

There is a belief that the threats may not be serious and could have been made by an attention seeker. But still, the manager and his family have been told to 'stay vigilant' just in case.

The incident has left all involved with Inter stunned, but it's just the latest blotch on Italian football this season. 

Already, a number of Serie A fixtures have been marred by racism. The first incident saw the Nerazzurri's striker Romelu Lukaku abused at Cagliari's Sardegna Arena back in September. 

More recently, Mario Balotelli was also subject to racist chants while playing for Brescia against Verona. 

These latest threats against Conte will cause a distraction, but the boss still has to prepare his team for their next fixture. 

Once the international break concludes, they face a trip to Torino, hoping to keep the pressure on Juventus. 

Inter are currently second in Serie A, just one point behind the leaders after 12 games and should the Old Lady slip up against Atalanta, the Nerazzurri could move top.