MANAMA: Bahrain has begun implementing a series of firm measures targeting individuals accused of undermining national security or acting against the interests of the state, including a review of citizenship entitlements, King Hamad bin Isa Al-Khalifa said on Sunday. The king said that steps included reassessing cases of Bahraini nationality where there were grounds to do so, with action to be taken in accordance with the law against anyone found to have betrayed the country or threatened its stability, the Bahrain News Agency reported.