Story highlights The "Trump Free Speech Rally Portland" is scheduled June 4; the #MarchAgainstSharia is set for June 10

Portland's mayor: The groups "are coming to peddle a message of hatred and of bigotry"

(CNN) The mayor of Portland, Oregon, is trying to stop what he describes as two upcoming "alt-right" demonstrations as his city continues to mourn the stabbing deaths of two residents who intervened in a possible hate crime.

Mayor Ted Wheeler on Monday called on the federal government to revoke the permit for a rally set for Sunday, and to deny permission for a second rally on June 10.

The two gatherings -- backed by different organizers -- are planned for a park on federal land, which gives federal authorities control over issuing permits.

"Our city is in mourning, our community's anger is real, and the timing and subject of these events can only exacerbate an already difficult situation," Wheeler posted on Facebook.

Two men suffered fatal stab wounds, and a third man was seriously injured, when they intervened in an incident on Friday on a Portland commuter train. Police said the men were trying to stop a man who was yelling anti-Musllim slurs at two young women -- one of whom was wearing a hijab -- on the train.