The US Supreme Court has ruled about half of Oklahoma belongs to Native Americans, in a landmark case that also quashed a child rape conviction.

The justices decided 5-4 that an eastern chunk of the state, including its second-biggest city, Tulsa, should be recognised as part of a reservation.

Thursday's decision in McGirt v Oklahoma is seen as one of the most far-reaching cases for Native Americans before the highest US court in decades.

The ruling means some tribe members found guilty in state courts for offences committed on the land at issue can now challenge their convictions.

Only federal prosecutors will have the power to criminally prosecute Native Americans accused of crimes in the area.

He referred to the Trail of Tears, the forcible 19th Century relocation of Native Americans, including the Creek Nation, to Oklahoma.

An analysis by The Atlantic magazine of Oklahoma Department of Corrections records found that 1,887 Native Americans were in prison as of the end of last year for offences committed within the boundaries of the tribal territory

They pledged to work with federal and state authorities to agree shared jurisdiction over the land