Feb 27 (Reuters) - Two Italians kidnapped on Friday in Nigeria's oil city Port Harcourt have been released, Italy's Foreign Ministry said on Monday. The ministry did not offer details. Italians Lucio Moro and Luciano Passarin had been working for construction company Impregilo <IPGI.MI>, when they were seized by gunmen. Violence surged in 2006 and it has worsened since the start of 2007. Following is a chronology of some major attacks and kidnappings involving the Nigerian oil industry this year. Jan. 12, 2007 - Nine South Korean workers and one Nigerian are freed after being kidnapped when gunmen attacked a base operated by South Korea's Daewoo Engineering and Construction in the Bayelsa state capital, Yenagoa, on Jan. 10. -- Jan. 16 - Three people, including a Dutch oil worker, are killed when their boat, operated by South Korean firm Hyundai, is attacked on its way to the Bonny Island export terminal. -- Jan. 18 - Gunmen free five Chinese telecom workers, kidnapped on Jan. 5 in Rivers State. One Italian is released in Bayelsa state. Three foreigners remain in captivity. -- Jan. 23 - Gunmen kidnap two engineers, one American and one British, in the southern oil city of Port Harcourt. The Briton is released on Feb. 7 and the American on Feb 17. -- Jan. 27 - A Belgian man working for a building materials company dies of gunshot wounds after gunmen ambushed him in Warri in the western Delta. -- Feb. 4 - Nine men working for the Chinese National Petroleum Company (CNPC), which was doing work for Shell in Bayelsa state, are released. They were kidnapped on Jan. 25. -- Feb. 6 - Gunmen abduct a Filipino worker on the road between Port Harcourt and Owerri. -- Feb. 7 - Gunmen kidnap a Filipina woman in Port Harcourt, the first known abduction of a woman in the region. -- A Frenchman, working on contract for oil giant Total, is kidnapped in Port Harcourt. -- Feb. 13 - Militants release all 24 Filipino crew members, who were captured when their cargo ship, belonging to German line Baco-Liner, was attacked on Jan. 20. -- Feb. 18 - Gunmen kidnap one Montenegrin and two Croatian oil workers, employees of Hydrodrive Nigeria, an offshore oil services company, in the Iwofe district of Port Harcourt. -- Feb. 23 - Gunmen shoot a Lebanese construction engineer in Port Harcourt. -- Feb. 26 - Two Italians, working for construction company Impregilo are released. They were kidnapped near Port Harcourt on Feb. 23.
