Imphal, Jan 20 (PTI) A hand-grenade was hurled at the house of an NPP supporter in Imphal East district in poll-bound Manipur, injuring a person, police said on Thursday.The incident happened late on Wednesday at the house K Loken in Arapti Awang Leikai in Irilbung police station area, which is in Keirao assembly segment, they said.In the grenade blast, Loken"s 27-year-old son suffered injuries on his right leg, police said.Director-General of Police P Doungel along with senior police officers visited the area following the incident.Those behind the grenade attack are yet to be identified, police said.Claiming that they do not have enmity with anyone, Loken"s family said they recently did not allow the BJP to put up its flag at their compound.With placards such as "Denounce Gun Culture", locals staged protest in the area, demanding immediate arrest of those behind the incident.Police said they are investigating the matter.On January 9, a BJP worker was killed along with an India Reserve Battalion (IRB) personnel in Imphal West district.Manipur will vote for its 60-member assembly on February 27 and March 3. The votes will be counted on March 10. PTI CORR SOM SOM