SOFIA - Bulgaria's parliament approved anti-terrorism legislation on Thursday that allows the government to curb civil rights during an emergency, signalling growing concern over the threat of Islamist militants.The changes, which were approved on a first reading and must be endorsed again, expand what police and security agencies may do in the event of a terrorist attack. Recent attacks in Europe have raised fears the Balkan country will be targeted. Several eastern European countries, including Poland and Hungary, have already approved anti-terrorism laws. Romania adopted similar plans.Human rights organizations criticized the measures, saying they carried dire implications for free expression and other human rights. Critics also said it is difficult to define when an anti-terror operation is needed.