The incident is just one of around 1,200 sightings recorded by investigators between 1987 and 1993, according to the files released by the National Archives on Sunday.

• 根据国家档案局星期日公布的文件，这个事件只是 1987 年和 1993 年间由调查人员报告的大约 1,200 个目击事件中的一个。