OKLAHOMA CITY (AP) - Federal authorities have set up a hotline to improve the reporting and investigation of crimes on tribal land in Oklahoma.

The action is in response to reports that crimes against American Indians by non-Indians are not being investigated and prosecuted as vigorously as they should be.

An Amnesty International report said the federal government is not doing enough to stop violence against Indian women. The report said Indian women are raped at a rate 2 1/2 times greater than non-Indians.

The head of the Oklahoma FBI, Michael B. Ward, said a perception exists that crimes occurring on Indian land, including sexual offenses, are not being addressed.

“Oklahoma's unique geographic dispersion of tribal land creates a potential for tribal crimes to go unreported due to confusion or lack of knowledge of where to report crimes,” Ward said.

To alleviate any confusion, he said crime victims or witnesses can call the new hotline to report serious crimes, such as sexual assaults. The number is 877-658-7423 (877-OK-TRIBE).