A huge, unstable chunk of glacier is blocking the route up Mount Everest from Base Camp in Nepal just as peak climbing season gets under way in the Himalayas. Icefall doctors – who fix ropes and ladders on the lower part of the route up the world's highest peak - can find no way round the 100-foot-high (30m) block of ice just under Camp 1. They say the only option is to wait for the ice block, called a serac, to melt – which they hope will happen within days.

The delay means preparations are weeks behind schedule for the spring season when weather for Everest ascents is usually best, and fears are growing that climbers will be queuing to reach the summit again this year. Purnima Shrestha, a prominent climber and photographer from Nepal, is currently acclimatising to summit Everest for the sixth time. We usually climb between Camp I, Camp 2 and Camp 3 back and forth during this acclimatising process. Delays in the opening of the route have added concerns of possible 'traffic jams' to the peak this year, she told the BBC from Base Camp.

The icefall doctors work for the Sagarmatha Pollution Control Committee (SPCC) that is responsible for securing ropes as far as Camp 2 on Everest, which stands 8,848.86m (29,031 feet) above sea level. By this stage in April they would normally have fixed the route as far as Camp 3, but are still blocked by the chunk of glacier about 600m below Camp 1. According to SPCC base camp coordinator Tshering Tenzing Sherpa, they haven't found artificial ways to melt the serac, meaning they can only wait for it to naturally melt and crumble.

There is a push by Nepal's Department of Tourism to explore alternative options, including airlifting rope-fixing teams to help facilitate the route. The department's director general, Ram Krishna Lamichhane, outlined plans of airlifting teams to ensure efforts can continue to open the route. Climbers hope the ice will melt soon so they can proceed safely to Camp 2 and beyond before the favorable weather window closes at the end of May. The ongoing blockage has heightened concerns about the narrow climbing window due to heavy competition among would-be summiteers this season.