Fifty of the 315 children kidnapped by gunmen from a Catholic school in Nigeria's Niger State on Friday have escaped. The Christian Association of Nigeria says they have been reunited with their families. A major military-led search and rescue operation is under way for the remaining 265 children and 12 teachers who were taken with them. Authorities in several Nigerian states ordered schools to shut following the mass abduction in Niger and another smaller hostage-taking in Kebbi state on Monday when 25 pupils were kidnapped from a boarding school.