SIX people, including two police officers, were killed in a gunfight at a remote property in Australia's Queensland state, authorities said, after police visited a home there to investigate a missing person report. When four officers arrived about 4:30 p.m. on Monday at the property in Wieambilla, about 300 km (186 miles) northwest of Queensland's capital, Brisbane, two armed people opened fire and killed two of them, police said, without identifying the suspects. Police said there was then a "siege" at the house, without elaborating. Police said 16 specialist officers responded and, in a gun battle about 10:30 p.m., killed…