Finnish police have revealed that the 12-year-old boy suspected of shooting and killing a classmate while injuring two others was a victim of bullying.

'The motive for the act has been identified as bullying. The suspect has told the police during interrogations that he has been the victim of bullying and this information has also been confirmed in the police's preliminary investigation,' police said in a statement.

They added that the young suspect had been transferred to the school at the beginning of the year and struggled to integrate with his new classmates.

It comes hours after a group of mourners gathered outside the school this morning to pay tribute to the child who was shot dead on Tuesday, April 2.

The Finnish government declared Wednesday a nationwide day of mourning, ordering all state agencies and institutions to lower the national flag to half-staff.

Many private households across Finland joined in the commemoration.

Heavily armed police on Tuesday cordoned off the Viertola school, an 800-student secondary school in the city of Vantaa, just outside Helsinki.

Police said the deceased boy died instantly after being shot.

The suspect was detained in the Helsinki area less than an hour after the shooting, with a handgun in his possession.

The minimum age of criminal liability in Finland is 15 years, which means the suspect cannot be formally arrested.

A suspect younger than 15 can only be questioned by the police before they are handed over to child welfare authorities.

The gun was licensed to a relative of the suspect who was not immediately identified. Police said he admitted to the shooting in an initial police hearing.

The Minister Petteri Orpo said the shooting was deeply shocking. He encouraged parents to comfort their children and help alleviate any fears about further such attacks.

'I want to tell children and young people all over Finland that the Finnish authorities and school staff are doing everything they can every day to prevent something like this from happening,' Orpo said in a statement.

Finnish Interior Minister Mari Rantanen said yesterday on X: 'The day started in a horrifying way...I can only imagine the pain and worry that many families are experiencing at the moment. The suspected perpetrator has been caught.'