WARSAW, Poland (AP) — Police in Poland used force Saturday to remove a few dozen protesters who tried to block a march in downtown Warsaw by a nationalist organization celebrating its anniversary.

The protesters chanted "Poland, free from fascism!" and sat down in the street as they waited for marchers from the National-Radical Camp to arrive.

The group, supported by Poland's nationalist government, was celebrating 83 years since its foundation. A few hundred members marched with white-and-red flags, chanting anti-migrant slogans.

Police detained and handcuffed some in the group protesting the march, since they had not obtained authorization for it. The new law regulating public gatherings was introduced by the conservative ruling Law and Justice party. Police also used force on journalists reporting about the event, pushing and even kicking them.

The nationalists' march was directed down a different route in the Polish capital to avoid clashes with their opponents.

Every march now must be authorized or face sanctions.