The police said gunmen shot journalist Tongam Rina from close range when she was entering office at about 6.15 pm.
Thirty-four-year-old Rina is associate editor of Arunachal Times, a popular daily newspaper, of Itanagar.
Chief Minister Nabam Tuki rushed to Ramakrishna Mission Hospital, where she is undergoing operation, after hearing the incident.
The police have launched a manhunt to arrest the culprits, sources said.
