(Top) Gangtok with its concrete jungle and the Tashiding monastery. File pictures

Gangtok, May 27: Two persons were killed in a quake-triggered landslip in South Sikkim yesterday.

As many as seven tremors, most of them between 3 and 5.5 on the Richter scale, were reported from several parts of the state.

Prakash Tamang, a resident of Darjeeling, and Ritesh Chettri of Kalimpong were buried alive when a pile of debris fell on them at a construction site on Ralong Road in Rabongla, 60 km from here. People watched in horror as Tamang, 25, and Chettri, 17, disappeared under almost 12 feet of loose soil after the 10 am quake. The bodies were dug out half-an-hour later by police and handed over to the families after post-mortem.

“Many of us did not feel most of the tremors during the day, but the last jolt around 5 pm was scary. It caused panic with people running helter-skelter,” said Ugyen Gyatso, a resident of Rabongla. Seven kilometres from there, in Ralong, four houses were destroyed. District collector (South) D. Anandan said the families were evacuated along with relief material and ex-gratia payments. He also said another house and an ICDS centre have developed cracks at Kewzing, 10 km from Rabongla, where a meeting of the disaster management committee will be held tomorrow. “While we cannot predict earthquakes, we can always ask people to be prepared,” said Anandan.

Sikkim has been witnessing a series of tremors since last Monday. There were three mild quakes that day followed by one that measured 5 on the Richter scale on the night of May 22. Monday’s earthquake caused damage to the Tashiding monastery, one of the oldest in Sikkim. Deep cracks have appeared on the walls while a roof with an iron cast has tilted. A survey team formed by the district collector (West) has inspected the more-than-200-year-old monastery. Many houses in areas surrounding Gyalshing, the West district headquarters, have also been affected.

Sankar Kumar Nath, a professor of IIT Kharagpur, however, has said the quakes were of a mild nature. “It was only 2 to 5 on the Richter scale and there is nothing to worry,” said Nath. He has prepared a report on the seismic hazard of the state and a microzonation atlas of the Sikkim Himalayas.

While the expert said he was yet to get all data on the recent tremors, it could have been caused by some movement along the neo-tectonic faults. Sikkim lies along four such faults. A fault is a thin zone of crushed rock separating blocks of the earth’s crust. An earthquake occurs when the rock on one side of the fault slips with respect to the other.

Nath said the “maximum credible earthquake” for Sikkim Himalayas, which falls in Zone 5 of the seismic atlas, is 8.3 on the Richter scale. “But this sort of quakes occurs generally every 500 years. The last major tremor was in 1934,” Nath said.