Digging through landslide debris, troops and relief teams are scrambling to rescue victims of the earthquake in remote mountainous areas in Sikkim after they reached an area here on Tuesday closest to its epicentre.  

The death toll in Sikkim rose to 50 after the 6.8 magnitude quake struck this Himalayan state and neighbouring areas on Sunday, officials said, adding the overall death toll in the region rose to 79.

In some silver lining for thousands of rescue personnel, the road connecting worst affected Mangan with the state capital Gangtok, 65 km from here, was reopened to help them make a quicker push towards isolated areas in what could be a herculean effort. However, fears of fresh landslides posed a threat to the reopened road.

 
helicopters here today following a slight improvement in the weather.

Officials here said that it could take three to four days to reach northern villages like Chungthang, about 55 kms from here, where people are feared trapped in debris.

"The road from Gangtok to Mangan is open. The number of deaths as reported by the Sikkim government is 50. This may increase further as rescue and relief teams reach into the interiors," Union Home Secretary RK Singh told reporters in New Delhi.

A correspondent visiting some of the quake-hit areas of Sikkim found the people still in a state of panic. They are so frightful that they are not entering their houses which have developed cracks or remained tilted after the calamity.

Many people were found sitting on roadsides, public places and near temples. Hundreds of people spent a second night in the open as aftershocks continued.

Rescue teams were also using explosives to try to force their way through blocked roads.

 
Stranded tourists have not yet been able to leave Gangtok and other places of the state as roads are either damaged or blocked by landslides.

"We can return only after the roads open. We are still in shock and cannot forget the trauma of the quake ... Most of the time we are staying outside," said Joy Basu, a resident of Sodepur near Kolkata visiting the mountain state with his family.

A bus carrying 22 people which went missing in north Sikkim since the temblor struck was yet to be traced.

A spokesman of the 17 Mountain Division said the bus could be anywhere in a radius of 10 and 15 km along the quake epicentre Mangan and Chungthang.

Official sources said efforts are on to clear the roads in the north district from Mangan, a small town ringed by snow capped mountains. It is hoped that roads upto Chungthang and Lachung would be opened by tomorrow.

The sources said relief and rescue operations have been stepped up by Army and National Disaster Response Force (NDRF) personnel with the improvement in weather.

"The biggest challenge now is to get the rescue teams to the affected areas," said Sikkim Information Minister C B Karki.

Food packets have been airdropped in inaccessible areas of the mountain state and round-the-clock work is on to clear debris and open roads still blocked due to quake-triggered landslides. District Collectors are overseeing the work.

The earthquake has left a trail of devastation damaging roads, houses and other structures, uprooting mobile phone towers and snapping communication and power lines.

Power and telephone lines have been restored in Gangtok. But the fringe areas of the town are still without power and are cut off from the rest of the world.

Communication links for areas outside Gangtok still remained disrupted.

1 Zone 5
2 Zone 4
3 Zone 3
4 Zone 2 
 
Zone 5Zone 5 covers the areas with the highest risks zone that suffers earthquakes of intensity MSK IX or greater. The IS code assigns zone factor of 0.36 for Zone 5.  Structural designers use this factor for earthquake resistant design of structures in Zone 5. The zone factor of 0.36 is indicative of effective (zero period) peak horizontal ground accelerations of 0.36 g (36 % of gravity) that may be generated during MCE level earthquake in this zone. It is referred to as the Very High Damage Risk Zone. The state of Kashmir, Punjab,the western and central Himalayas, the North-East Indian region and the Rann of Kutch fall in this zone.The capital of India,Delhi,also lies in this zone.

Generally, the areas having trap or basaltic rock are prone to earthquakes.

Zone 4This zone is called the High Damage Risk Zone and covers areas liable to MSK VIII. The IS code assigns zone factor of 0.24 for Zone 4. The Indo-Gangetic basin and the capital of the country (Delhi), Jammu and Bihar fall in Zone 4. In Maharashtra Patan area(Koyananager) also in zone 4.

Zone 3The Andaman and Nicobar Islands, parts of Kashmir, Western Himalayas fall under this zone. This zone is classified as Moderate Damage Risk Zone which is liable to MSK VII. and also 7.8 The IS code assigns zone factor of 0.16 for Zone 3.

Zone 2This region is liable to MSK VI or less and is classified as the Low Damage Risk Zone. The IS code assigns zone factor of 0.10 (maximum horizontal acceleration that can be experienced by a structure in this zone is 10 % of gravitational acceleration) for Zone 2.