Human Rights Watch documented and evaluated the impact and effects of the NATO military operation, and confirmed 90 incidents in which civilians died as a result of NATO bombing. These included attacks where cluster bombs were dropped.[50] In 1999, it was estimated that 488–527 Yugoslav civilians died as a result of NATO bombing.[51] The report also criticized Pentagon and NATO officials for a lack of attention to the issue of civilian deaths, suggesting "a resistance to acknowledging the actual civilian effects and an indifference to evaluating their causes."[52]