A fire at an oil refinery burned itself out early Monday, five hours after an explosion killed at least three, hurt 12 and shook homes more than a mile away, officials said.

The extent of damage at the Citgo Petroleum Corp. refinery, about five miles from Lake Charles, was not immediately known. The explosion occurred about 11 p.m. Sunday at the plant's catalytic cracker unit, which is used in refining.Plant spokesman Bob Davidson said damage at the refinery could not immediately be determined.