June 1 (Reuters) - Gunmen used dynamite and heavy machineguns to kidnap at least three senior managers of Indonesian chemical company Indorama from their residential estate in Nigeria's oil-producing delta, police said on Friday. Below 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 two days after being kidnapped from the Bayelsa state capital, Yenagoa. -- Jan. 16 - A Dutch oil worker and two other people 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 workers kidnapped on Jan. 5 in Rivers State. An Italian is also released. -- Jan. 23 - Gunmen kidnap two engineers, one American and one British, in the southern oil city of Port Harcourt. They are released in February. -- Jan. 27 - A Belgian working for a building materials company dies of wounds after gunmen ambush him in Warri. -- Feb. 4 - Nine men working for the Chinese National Petroleum Company, which was doing work for Shell in Bayelsa, are released after being 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. He is rescued by troops on March 16. -- Feb. 13 - Militants release all 24 Filipino crew members captured when their cargo ship, belonging to a German company, was attacked on Jan. 20. -- Feb. 18 - Gunmen kidnap one Montenegrin and two Croatian oil workers, employees of Hydrodrive Nigeria, in Port Harcourt. They are rescued by the military on March 12. -- Feb. 23 - Gunmen kill a Lebanese construction engineer in Port Harcourt. -- Feb. 26 - Two Italians working for a construction company are released. They were kidnapped near Port Harcourt on Feb. 23. -- Feb. 28 - Gunmen kidnap a Lebanese construction worker who was employed by a local firm in Rivers state. -- March 8 - A Filipino oil contractor is freed. -- March 14 - Militants release two Italian workers they had been holding hostage since Dec. 7. -- April 4 - A Dutch manager for German building contractor Bilfinger Berger, kidnapped in Port Harcourt on March 23, is released. A British worker, abducted from the Bulford Dolphin oil rig on March 31, is freed. Two Lebanese employed by Setraco who were abducted in Bayelsa on April 2 are also released. -- April 7 - Gunmen kidnap two Turkish engineers from their car in Port Harcourt. One works for Merpa, a Turkish firm that maintains telecommunications on oil platforms. -- April 27 - Gunmen kill two policemen in a failed kidnap attempt in Port Harcourt as the officers were escorting a convoy of vehicles carrying expatriate staff to work. -- May 1 - Four Italian oil workers are kidnapped. -- May 3 - Gunmen kidnap 20 foreign workers in three attacks in the Niger Delta region but eight were freed within hours. -- June 1 - Gunmen kidnap at least three senior managers of Indonesian chemical company Indorama from their residential estate in Nigeria's southern oil-producing delta.
