WASHINGTON - U.S. troops have found a suspected chemical factory in Iraq and officials were trying to determine late Sunday whether it was involved in making chemical weapons, U.S. officials said. The plant is near the city of An Najaf, which U.S. troops reached Sunday on a push to Baghdad, the officials said. President Bush and other U.S. officials say ridding Saddam Hussein's regime of chemical and biological weapons is the main objective of the war. Saddam's government denies it has any chemical, biological or nuclear weapons or programs to produce them. Asked at a news conference in Qatar Sunday...