The Metropolitan Police Department on Friday asked five companies and one individual that administer seven Web sites to delete child pornography-related data from the sites, which introduce and rank Internet child pornography, police said.

This is the second such request after the first one in April that urged four firms, in Tokyo, Kanagawa and Hyogo prefectures, to delete such data from 14 sites.

The seven Web sites direct Internet surfers to sites that contain about 2,960 child porn images, roughly 90 percent of which are of boys, the police said.