The explosion occurred in connection with an eviction attempt in Castel d'Azzano, just south of Verona, when the police forced the front door to the residence, which was filled with some form of gas.
Two people, a brother and sister in their 60s, could be arrested, while a third family member fled, writes Italian Ansa.
The news agency's sources state that the plan was to evict three siblings who had previously threatened to blow themselves up in the air.
Most of the injured are police officers, but a private person was also injured.
