Chief of Army Staff General Dalbir Singh is on a visit to Manipur and Assam to review security situation, an official said."General Dalbir Singh visits Manipur and Assam to review security situation (in the states)," the Indian Army said in a tweet on Saturday.The United Naga Council has imposed an economic blockade in the state since November 1 to denounce the creation of seven new districts from areas inhabited by Nagas in Manipur.Singh is set to retire on December 31 and will be succeeded by Lt. General Bipin Rawat.