Saudi Arabia's Eastern Province is home to many of the country's minority Shia population. Many there have long complained of marginalisation at the hands of the Sunni ruling family.Shia people saying they are poorer than the Sunni despite living on one of the world's largest oil fields. In a special investigation for the BBC's Our World, Saudi journalist Safa Al Ahmad has gained unprecedented access to film in the region. She spoke to activists, some of whom were on the government's most wanted list, and uncovered how the Shia community was reacting to a violent government crackdown.