They said about 100-metre long portion of the national highway sank due to heavy rains in the past few days at the place near Kohima since Friday night.
Several vehicles, including trucks which were coming from Assam to Manipur, were stranded, they said, adding personnel of Border Road Task Force (BRTF) were working round-the-clock to mend the damaged portion of the national highway.
Transport services, including tourist buses between Manipur and neighbouring states along this highway have been suspended, they said, adding that some trucks and buses were plying along the second Imphal-Jiribam-Silchar NH 53 but this route was not dependable.
NH 53, which was blocked for some days recently due to damage of a bridge following heavy landslide at Nungdolan area, about 60 Kms from Jiribam, was opened only a few days ago.
The two national highways particularly Imphal-Dimapur-Guwahati are considered lifeline of land-locked Manipur as people who want to go to different parts of the country use these two routes through which essential and daily need items were also brought in the state.
Reports from the markets said essential items were still available although the stock was dwindling day by day.
Prices of several items may go up in the next few days if there was no supply of various daily need items, reports said, adding social organisations have appealed to the traders and businessmen to control the prices in view of the landslide on the national highway.