``The geologists have repeatedly warned the authorities to avoid eco-tourism in such highly sensitive zones,'' A R Bhattacharya and Rameshwar Bali of the geology department at the Lucknow University said here.

The two geologists, who have worked extensively on the Himalayan geology and at Dharchula about 60 kms from the scene of landslide, said rocks have been under ``great stress and were weak and fragile''.

The Kailash-Mansarovar pilgrimage route via Malpa has been a traditional route for many years. The fibre-glass huts that were erected for the pilgrims at Malpa were very weak and heavy rain in the region had aggravated the problem and caused the worst evermishap, the geologist duo said.

More than 200 people, including 60 Kailash-Mansarovar pilgrims, were feared buried alive in the massive landslide on Tuesday last in Malpa village.

Bali said before undertaking any eco-tourism activity the ``micro level zoning'' from geological point of view should have been assessed first.

Bhattacharya said heavy rainfalls triggered the landslides in the area when faults in the rocks became ``active''.

Bali said the region was found to be very sensitive. ``There are debris-cone structure in the rocks which get weakened during rain and cause landslides.''

On the series of landslides reported during the last ten days killing 308 people in Garhwal and Kumaon hills, Bhattacharya said, ``These are culmination and cumulative effects.''