Womenfolk of Sangaiprou area today staged a sit-in-ptotest near FCI godown Sangaiprou in protest against bomb threat to the residence of Block development Officer Khungdongbam Chaoba Singh at Sangaiprou. Mentioned may be made that unknown miscreants hurled a Chinese made hand grenade at the residence of the BDO at around 7.30 am yesterday but the bomb failed to explode. A police team had collected the hand grenade.