Istanbul Governor Vasip Sahin has banned an LGBT Pride march scheduled to take place on Sunday.

Sahin, who oversees Turkey's most populous city, cited security concerns in making his announcement.

Istanbul's LGBT march is considered to be the largest in the Muslim world. Authorities cited similar concerns in blocking last year's event.

Last week, the ultra-nationalist Alperen Hearths group threatened the marchers.

“If the state allows it, we will not,” said Kursat Mican, who helms the group's Istanbul chapter. “We will not allow them to walk. Wherever they march, we'll also go. We will close down that street and they will not be able to go there.”

During a television interview aired on Cultural TV, Mican claims that LGBT activists were organizing to prevent heterosexuals from reproducing: “By popularizing homosexuality, they want to destroy the unity of family, stop reproduction, end relations between wives and husbands, and prevent children born in such relations from growing up to be propitious to their land and country,” he said.

Organizers behind Sunday's planned march in Taksim Square released a statement headlined: “We are Marching, Get Used to it. We are Here, Not Going Away.”