The assembly of northwestern Khyber Pakhtunkhwa province has approved a bill to merge the tribal region along the Afghan border with its territory, paving the way to granting equal rights to about 5 million people in the restive area.

Sunday's milestone step comes after both houses of parliament had earlier approved granting equal rights to the tribes that have been governed by discriminatory laws since British colonial rule.

The bill now goes to President Mamnoon Hussain to be signed into law.

The regions remain effectively lawless and in recent years has become became a haven for militants.