KIRKUK, Iraq _ The body of a Christian health worker turned up in a field two days after he was kidnapped _ prompting several more Christian families to pack up and leave their ancient homeland in northern Iraq. At least 10 Christian families have left Kirkuk in recent weeks, fearing kidnap-for-ransom gangs that have turned their sights on Christians in one of Iraq’s most ethnically diverse cities. Recent violence and abductions have prompted Kirkuk’s archbishop to demand government protection against what he has called religious-driven “terrorism.” Attacks are not new against Iraq’s small but historically significant Christian community. Its roots stretch back to the early centuries of the faith and include areas mentioned in the Bible. The last official Iraqi census in 1987 found 1.4 million Christians in the country. Now, according to the 2008 U.S. State Department report on International Religious Freedom, that number has dropped to between 550,000 and 800,000. Some estimate the number is even lower.