Guwahati, Jan 8 (IANS): NIA chief Sharad Kumar Thursday visited some of the violence-affected areas in Assam's Kokrajhar district and reviewed the investigation into the militant attacks that left over 70 dead and rendered two lakh homeless.

The National Investigation Agency director general visited Lungshung, Ultapani and Pakhiriguri areas in the district where militants of the National Democratic Front of Bodoland (NDFB) anti-talk faction had fired indiscriminately at civilians Dec 23, killed 33 people including women and children.

Sharad Kumar had Wednesday visited violence-hit areas of Sonitpur district, and interacted with police officials and the NIA team, which reached the state earlier this week.

The NIA chief, however, refrained from making any comment about his visits.

The NDFB had launched attacks almost simultaneously in Kokrajhar, Chirang and Sonitpur districts Dec 23, killing at least 78 people including 21 women and 19 children. Three people were killed when police fired at protesters the following day.

The violence triggered massive displacement in the three districts and neighbouring Udalguri. Over two lakh people took shelter in over 100 relief camps.

The situation has improved considerably in the four districts in the last few days with no reports of any untoward incident.

The Assam government has registered 102 cases regarding the violence and 58 people have been arrested. Four cases have been handed over to the NIA.

The army and police have intensified operations against the NDFB, particularly along the international border with Bhutan.

The Assam State Disaster Management Authority said people have started returning to their homes and nine relief camps have been closed since Wednesday.

"There are now 1,22,725 inmates in 68 relief camps in the four districts," an official said.