Condemning the kidnapping and subsequent murder of the eight-year-old daughter of Manipur General Administration Minister Francis Ngajokpa, Defence Minister George Fernandes today appealed to the militants in the state to stop kidnapping children for ransom and join the mainstream.‘‘My appeal is don’t kidnap children for money. Militants should lay down arms, join the national mainstream and earn money by participating in development work,’’ he told the media at Kangla here after addressing NCC cadets. The Minister, who concluded his two-day visit today, also reviewed counter-insurgency operations in the state. Meanwhile, the police said they are hopeful of a breakthrough in the case. ‘‘We have received concrete proof and are zeroing in on the killers’ identity,’’ Director General of Police (DGP) Y. Joykumar said. ‘‘The 11 people picked up in connection with the murder of the girl were interrogated and we have got some evidence, which might prove that some of them were involved in the crime,’’ Joykumar said.