New Delhi, July 23 : Taking serious view of the situation in Manipur in view of the blockade imposed by All Naga Students Association, Left parties today asked the Centre to take urgent steps to restore normalcy and ensure that essential commodities reach people in the trouble-torn State.

In a letter to Prime Minister Manmohan Singh, leaders of four Left parties sought Centre's intervention to end the ''present impasse" and extend full security and protection to the two national highways, NH-39 and NH-53, and restore road and other modes of communication.

They observed that despite best efforts by the State Government, the students' association has been blocking highways and had even claimed responsibility for breaking a bridge on NH-53.The letter, signed by Prakash Karat (CPI-M), AB Bardhan (CPI), Debabrata Biswas (Forward Bloc) and Abani Roy (RSP), said essential commodities were also not reaching the State with rice being sold at a rate of Rs 50 per kg and diesel at Rs 80 a litre.

"It is as if the people of Manipur are in a State of siege", the Left leaders said.