Another eight people, who were travelling in a bus of Teesta Urja Limited, are presumed dead as their vehicle got stuck under the debri of a landslide caused by the 6.8 magnitude tremblor last evening, Major General S L Narasimhan, GOC 17 Mountain Division, told reporters here.
The overnight toll climbed to 50, with 23 people being killed in Sikkim, six in West Bengal, seven each in Bihar, Nepal and Tibet, official reports said.
Over a hundred people have been injured in the quake which has left a trail of devastation in Sikkim, causing hindrances in relief work because of landslides and road blockades, they said.
Narasimhan said army has launched ''Operation Madad'' in Gangtok and other areas by deploying over 2,000 troops.
"Around 44 columns of army are working in various parts of Sikkim, while another 15 are in the East District of the state. We are also sending teams to Darjeeling and Kalimpong (in West Bengal)," he said.
Two districts -- West and South -- in Sikkim remained inaccessible to the army, delaying rescue work, he said, adding that the local authorities were carrying out relief work and army commanders stationed there have been alerted.
The casualties have occurred mostly in the North District and in towns and villages like Rangpo, Dikchu, Singtam and Chungthang located along the course of Teesta river, officials said.
A group of 14 tourists were rescued by the army from north Sikkim last night, Narasimhan said. In Delhi, Prime Minister Manmohan Singh announced Rs two lakh as ex-gratia to next of kin of those killed in the earthquake and Rs one lakh each for those seriously injured.