Imphal, Aug 22 : Blockade on the Imphal-Dimapur National Highway (NH-2) continued for the second day on Tuesday, while the security forces provided security cover to facilitate the movement of vehicles along the Imphal-Jiribam National Highway (NH-37). A police officer in Imphal confirmed that movement of vehicles along NH-37 with essential items have been ensured. 'Strict security measures have been taken in all vulnerable locations and security convoy has been provided in the sensitive stretches in order to ensure free and safe movement of vehicles,' the officer said. Due to the blockade on the NH-2, the supply of essential items and food grains were affected in many parts of the tribal-dominated areas. There are also blockades in some patches on the NH-37, partially affecting the movement of vehicles. The Committee on Tribal Unity (COTU) had on Monday reimposed blockades at a few places on NH-2 in Kangpokpi district and NH 37 in Tamenglong district, demanding uninterrupted and adequate supply of foodgrains, essential commodities and medicines to the mountainous areas inhabited by Kuki-Zo communities. Officials said that a large number of men and women in Kangpokpi district enforced the blockade and prevented movement of goods-laden vehicles. COTU General Secretary Lamminlun Singsit said, "We had earlier given an ultimatum that we would block both NH-2 and NH-37 from August 21 if uninterrupted and adequate supply of food grains, essential commodities and live-saving drugs is not ensured to the tribal areas." Another tribal organisation, Kuki Zo Defence Force, had also announced that it would join the highway blockade if supply of essentials are not made to the Kuki Zo inhabited areas. NH-2, the surface lifeline of Manipur, was blocked for nearly two months after ethnic violence broke out in the state on May 3. With the intervention of the Central government, the blockade was withdrawn last month. The NH-2 and NH-37 are the two vital National Highways of Manipur to maintain surface communication with the rest of the country via Nagaland and Assam. /IANS