Kolkata, August 07: The move to open alternative routes to Manipur, affected by the economic blockade, has run into problems as stretches of those routes pass through terrorist-infested areas, Defence Minister Pranab Mukherjee said today.

�Certain alternative routes were identified, but those pass through areas infested with terrorists.

The Silchar-Jiribam Road is also not safe.

Therefore, search is on for new alternatives,� Mukherjee told reporters here.

�This blockade, unfortunately has been a long one.

Whenever there is an agitation in any part of the North-East, the first casualty is the communication system.

They do not understand that this affects the common people and not the policy makers,� Mukherjee said.

He said the Centre was in constant touch with the Manipur Government in a bid to resolve the problem.

Around 40 tonnes of essential items, including life-saving drugs, were airlifted to Manipur from Guwahati yesterday.

The ANSAM launched the economic blockade on June 20 last in protest against a Government decision declaring June 18 as a holiday to observe �State Integrity Day�.

According to ANSAM, it was against the plan for unification of Nagas.

However, many social groups supported the Govt�s decision.