The deaths of an Irish and a British climber on Mount Everest bring the toll of fatalities on the world's highest peak to 10 in one week.

Expedition organisers said on Saturday that British climber Robin Fisher, 44, reached the summit on Saturday morning but collapsed when he had travelled just 150 metres back down the slope.

"Our guides tried to help but he died soon after," Murari Sharma from Everest Parivar Expedition told AFP.

Irish citizen Kevin Hynes, 56, passed away on Friday on the northern Tibet side of the mountain during his descent.

A father of two, he turned back before reaching the mountain's peak and died in his tent at 7,000 metres.

READ MORE: This remarkable picture shows the deadly overcrowding on Mount Everest

It came during a season that has been plagued by bad weather and overcrowding on the peak.

Nepali officials said on Friday that some climbers were getting caught in the crowds on the mountain and this was leading to exhaustion, dehydration and in the worst cases death.

An impressive photograph showing people queuing to reach the summit was posted on social media (pictured in the main image of this story), with a climber complaining of "heavy traffic" totalling around 320 people.

Nepal is facing criticism over the fact it has issued a record 381 permits for the Spring season this year — costing $11,000 (€9,815) each.

Some are calling for a cap to be placed on the number of climbers permitted on the mountain.

Among the other deaths this week were four people from India, one from Nepal, an Austrian and an American.

Nihal Bagwan, one of those who died this week, had been "stuck in the traffic for more than 12 hours and was exhausted," local tour guide Keshav Paudel told AFP.