A Nigerian bandit chief who led the kidnapping of hundreds of schoolchildren has been killed in armed clashes with a rival gang, days after reneging on an amnesty deal with authorities, sources told AFP. Awwalun Daudawa led the abduction of more than 500 students from Government Science Secondary School Kankara last December. It was one of a series of mass abductions by heavily armed criminal gangs who have become an increasing security challenge in northwest and central Nigeria. On Thursday a Zamfara state government official told AFP Daudawa had reneged on a peace pact he made in February and returned to lead his men in the forest.