Investigators say the elementary-aged girls were walking to school, and told their teacher they saw a man masturbating as they passed a bus stop.

Nigeria's military reports rescuing a second Chibok schoolgirl in a forest battle with Islamic extremists, but a community leader says she is not on the list of 218 students missing from the 2014 mass abduction by Boko Haram.

The United Nations human rights office says there have been threats, violent attacks and other abuse against girls for going to school in at least 70 countries over the past five years.