Militants sabotaged major crude pipelines in Nigeria''s chaotic oil region on Monday, further trimming crude production as the military widened an operation to uproot the fighters, the Associated Press reports. The Movement for the Emancipation of the Niger Delta said it had destroyed pipes run by Chevron Corp. before dawn in Delta State, where the military is carrying out its largest operation in years against militants. Chevron confirmed an incident on its pipeline network and said it caused them to shut down operations totaling 100,000 barrels per day. The militants said they had released three Filipino hostages seized this month. The military launched its operation in Rivers State nearly two weeks ago, after rare clashes between armed forces and the militants in the Scotland-sized region of swamps, rivers and creeks. The militants say they have killed at least 12 soldiers, and the military says it is searching for 11 troops missing in the area. The militants say they are fighting to force the federal government to send more of the oil-industry funds it controls to the Niger Delta, which remains deeply impoverished despite five decades of oil production. But criminality and militancy are closely linked, with many leaders of the militant groups growing rich by stealing oil from pipelines and selling it overseas. An upsurge in violence that began in early 2006 has seen hundreds of foreign workers kidnapped and dozens of attacks on crucial oil infrastructure. Hostages are normally released unharmed although several have died during botched snatch or rescue attempts, including two other Filipino hostages killed as violence flared this month. Militant activities have trimmed Nigeria''s daily oil output by about 25 percent off pre-2006 heights, with the country producing about 1.6 million barrels per day now. The government says no more production has been lost in the recent violence.