On the eve of King Gyanendra's visit to India, the Maoists launched a campaign to cripple the country by blocking off all main highways in Central Nepal with booby-trapped barricades.

For Kathmandu Valley, this is effectively another blockade since all four highways linking the capital to the rest of the country have been blocked for two days now. Shops are hoarding vegetables and food, and queues have formed at petrol stations.

Early Wednesday morning, 18 lorries on the East-West Highway were burnt to cinders by the Maoists for defying their blockade. The army has been hard-pressed to clear the barriers and carried out heli-patrols along the main highways on Thursday.

A day after six policemen were killed in the first ever attack on a post inside Kathmandu Valley, the chief of the Maoist eastern command, Comrade Badal, said on Sunday, it marked the beginning of the rebel's 'strategic offensive' phase.

On a trip this week from Pokhara to Biratnagar, we saw thousands of passengers forced to spend cold nights huddled inside buses, many had run out of money to pay for food. There are bombs hidden inside trees and boulders piled on the highways and are too risky to remove.

"Driving was already risky because of accidents and robberies, but the landmines have made it even riskier," says Dhiraj Rai, a bus driver. The Maoists are replicating tactics they used in western Nepal last month by blocking highways and ambushing the army as it tried to clear them. Seven soldiers were killed in an ambush on the Jiri Highway on Saturday.

All over eastern Nepal, along the East-West and Mechi highways, tree trunks and boulders have blocked roads. The barricades are festooned with Maoist banners and from the nearby forest the Maoists warn bus passenger through loudspeakers not to remove the trees. "Don't move them, we won't be responsible if you are killed," they say.

Major Kosh Raj Ghimire from the Ilam barrack says it is difficult to clear the barricades because of the bombs and the danger of Maoist ambushes. "There are so many of these obstructions, it takes time," he told worried bus passengers on their way to Mirik on Wednesday.