 News agencies in Japan say the Defence Ministry is investigating how one of its warships came to enter Chinese territorial waters last week. Beijing has described the Navy destroyer's brief incursion off the eastern province of Zhejiang as an intentional provocation. China was conducting a live-fire drill in the area at the time and had declared it a no-sail zone. Papua New Guinea's Petroleum Minister Jimmy Maladina has pleaded not guilty to assaulting a woman in the Australian city of Sydney.