More than 100 people have been killed after a series of avalanches were unleashed by heavy snowfall in northeastern Afghanistan, the worst to be experienced in three decades, Reuters reported.

The mountainous province of Panjshir, where avalanches are common, has already had two days of heavy snowfall and the snowstorm is expected to last another two days, local officials said on Wednesday, adding that the death toll is expected to rise while "many more" people remain missing.

"We haven't seen this much snow, or this many avalanches, for 30 years. If the central government doesn't provide humanitarian support, machinery and food soon, this will turn to a disaster," said Abdul Rahman Kabiri, the governor for Panjshir province, describing it as an imminent humanitarian emergency.

"The roads are closed and many villages are disconnected," Kabiri said. "There have been several big avalanches across the valley and in parts of the valley, it snowed one meter."

Local authorities have had "very limited resources" to deal with the situation, Kabiri added, stating that he had called on the central government for help and been "assured that the needed machinery and rescue teams will get to us soon."

With snow suddenly sweeping through villages and blocking off roads for the past two days after an unusually dry winter led to fears of drought, more than 20 people have been left injured, according to NBC News.

In an attempt to rescue survivors, rescuers in some areas have been forced to use their bare hands and shovels to dig the victims out.

Meanwhile the snow is vital for Afghanistan, where about three quarters of the rural population dependent on agriculture relies on snow melting in the mountains to sustain crops in the spring and summer, the U.N. Food and Agriculture Organization estimated in 2004.

"Now we are optimistic about the agriculture situation around the country," Ministry of Agriculture spokesman Lotfullah Rashid said.

"There will be snow and rain for several days, so the country won't face a lack of water during the coming year. If there hadn't been this much snow and rain, next year could have been a disaster," Rashid added.

For now, the situation remains "precarious" because of the lingering possibility of more avalanches. "The toll could rise as we are still getting reports of new incidents," he said.