Pakistan's parliament has passed a law guaranteeing basic rights for transgender citizens and outlawing discrimination by both employers and private business owners, a move hailed by activists as "historic" for the conservative South Asian country.

Members of parliament voted to pass the wide-ranging Transgender Persons (Protection of Rights) Act in the capital, Islamabad, on Tuesday.

The law accords citizens the right to self-identify as male, female or a blend of both genders, and to have that identity registered on all official documents, including National Identification Cards, passports, driver's licenses and education certificates.