Home Minister P. Chidambaram said Friday that he has written to Prime Minister Manmohan Singh accepting full responsibility for the massacre of 76 security personnel in Chhattisgarh, the worst Maoist attack since the insurgency started four decades ago.

"I accept full responsibility for what happened in Dantewada," said Chidambaram, adding that he has no hesitation to accept that the buck stops at his desk.