More than 200 gunmen killed in Nigeria security operation -official

KADUNA, Nigeria (Reuters) - At least 200 gunmen were killed in the past three days in Nigeria's central-northern state of Niger during a security operation to clear armed gangs from the area, a state commissioner said on Thursday.

Gunmen have terrorised citizens in the north and northwest of the country and have gained notoriety for kidnapping hundreds of students and villagers for ransom and killing dozens.