JUDY WOODRUFF:

It's fair to say a reign of terror grips the Philippines, as its president, Rodrigo Duterte, wages a brutal war on drug dealers and users.

According to Human Rights Watch, more than 7,000 people have been killed in just the last nine months. But who exactly is doing the killing?

This story was reported by Kara Magsanoc-Alikpala and narrated by William Brangham.