A UN human rights investigator hoped to meet detainees at Myanmar's notorious Insein Prison on Thursday, a day after the ruling junta defied global calls to halt its crackdown by arresting three more anti-government activists. Paulo Sergio Pinheiro was sent by the UN to investigate allegations of widespread abuse during the junta's bloody September crackdown on pro-democracy protests. His five-day mission, which ends Thursday, was aimed at getting inside Myanmar's prisons to determine the numbers of people detained and killed by the regime. The military government said 10 people were killed when troops opened fire on crowds of peaceful protesters September 26 and 27. Diplomats and dissidents, however, say the death toll was much higher. The government has acknowledged detaining almost 3,000 people but says it has released most of them. Many prominent political activists, however, remain in custody.