A landslide Saturday killed eight people in Nepal with mud and rocks crashing down and blocking the Sun Koshi river.
A small village has also been buried with at least 150 people reported missing.
Following the landslide that occurred at about 2 a.m. Saturday morning, the river has formed a large lake in Sindhupalchowk district, about 60 km from here.
It is feared that once the blocked water is released, it will result in massive flooding in Nepal and India's Bihar.
Nepal's ministry of home affairs has urged the local administration of Sunsari district where the Kosi barrage is located, to open the 56 gates.
"The massive rise in the water level may hit the barrage, so we have instructed the ministry of home to open the gates of the Kosi barrage," said Yadav Koirala, joint secretary in Nepal's ministry of home affairs who looks after disaster management.
Nepal's ministry of home affairs has also declared a state of emergency in the affected areas and sought help from India and China to prevent loss of lives and property.
Nepal Police spokesperson Ganesh K.C. said authorities were trying to conduct a controlled blast to funnel off the water.
The landslide has also buried Arniko highway at the dam site in Mankha VDC, bringing traffic on the road linking Nepal with China to a standstill.
Residents of Barhabishe, Lamesanghu, Khadichaur and Dolalghat villages in Sindhupalchowk district besides other surrounding areas have moved to higher grounds, fearing the blocked river may burst through anytime.
Chief District Officer Gopal Prasad Parajuli said the administration has been considering dropping a bomb from a Nepal Army chopper to clear the landslide debris, so the river could have a free flow.
Meanwhile, Prime Minister Sushil Koirala has directed the home ministry to look at controlled release of water from the blocked river and to take steps to protect the lives and property of people.
The PM's secretariat issued a press statement Saturday and directed the authorities to coordinate among themselves to avert the crisis.
