Neighbouring Assam was put on high alert by the Centre following the incident in Dimapur.
One person was injured in police firing on the mob and he later succumbed to his injuries, Meren Jamir, Superintendent of Police of Dimapur, said, adding in all four to five people had sustained injuries in the action.
He said curfew remained in force in Dimapur where the situation was "under control."
Asked to comment on reports that the rape accused was a Bangladeshi immigrant, Jamir said "I cannot tell you anything on that now and it is a matter of investigation."
Posse of riot police personnel patrolled the streets of Dimapur.
Chief Minister T R Zeliang said a high-level inquiry has been ordered into the mob attack to ascertain if there had been any lapse in security.
The Centre meanwhile today sought a report from Nagaland government on the lynching of the rape accused by a mob and put neighbouring Assam on high alert in the wake of the incident.
Home Minister Rajnath Singh said that he has already discussed with senior officials about the incident and asked them to take necessary action.
The central government has also alerted neighbouring Assam and asked it to step up vigil so that no untoward incident takes place along its border with Nagaland, officials said.
Zeliang today assured Assam Chief Minister Tarun Gogoi that necessary action would be taken against those who had broken into Dimapur jail and lynched the rape accused.
Zeliang also said if there were lapses on part of the officials, then necessary steps would be taken against them too.
