MILAN (AP) — Hundreds of demonstrators clashed briefly Sunday with riot police ahead of a meeting between Silvio Berlusconi and a hotly contested right-wing political leader in the northern city of Bologna.

Violence broke out when demonstrators kicked riot police shields and police responded by forcing them back with batons, video footage showed. Italian news reports said at least one officer was injured by an exploding firecracker.

Hundreds gathered to protest the arrival of Northern League leader Matteo Salvini, whom they decry as a racist for his anti-migrant views. Saboteurs overnight set fire to railway cables that shut down the heavily traveled Bologna-Milan line for several hours. They left behind anti-racist graffiti.

Berlusconi, who has been largely sidelined from politics since his tax fraud conviction, was meeting with Salvini and the leader of another center-right party to discuss an alliance to unseat the Democratic Party in the next election.

The Northern League was a junior partner in Berlusconi governments, but the dynamics have since shifted. Berlusconi has been weakened by the tax fraud conviction and another for paying for sex with an under-age prostitute, while Salvini's popularity has surged since the last election.

"This isn't a return to the past," Salvini told reporters. "Something new is starting here, that is led by the Northern League, but is open to all Italians who today are far from politics."