Transgender people can be especially vulnerable to harassment and attacks and shouldn't be equated with gays and lesbians by U.S. immigration officials determining whether to grant asylum, a federal appeals court said Thursday.

The San Francisco-based 9th U.S. Circuit Court of Appeals issued the ruling in the case of a transgender Mexican woman who sought shelter in the U.S. on the grounds that she would likely be tortured if returned to Mexico.

Edin Avendano-Hernandez said she had been sexually assaulted by uniformed Mexican police and a military official for being transgender.

The Board of Immigration Appeals wrongly relied on Mexican laws protecting gays and lesbians to reject Avendano-Hernandez's asylum request, the ruling states.

The 9th Circuit said transgender people face a unique level of danger and are specifically targeted in Mexico by police for extortion and sexual favors.

"While the relationship between gender identity and sexual orientation is complex, and sometimes overlapping, the two identities are distinct," Circuit Judge Jacqueline Nguyen wrote. "Significant evidence suggests that transgender persons are often especially visible, and vulnerable, to harassment and persecution due to their often public nonconformance with normative gender roles."