Forty-nine people lost their lives to extreme dehydration in a remote corner of the Sahara Desert in Niger after the truck carrying them broke down, local authorities reported Thursday.

The victims were part of a group returning from Mali, where they had attended a Muslim festival, when their vehicle failed in an isolated area more than 80 kilometres (50 miles) west of Assamaka, according to the Agadez governorate.

“Deprived of water and unable to repair the vehicle despite the efforts of the driver, his assistants and the passengers, the travellers found themselves trapped in the heart of a hostile environment where extreme temperatures and the absence of supply points make survival extremely difficult,” the governorate said in a statement posted on official social media account.

The 49 victims were buried in mass graves in the desert.

Two survivors endured a harrowing journey on foot, walking more than 50 kilometres to reach a water source before continuing to Assamaka. From there, they alerted authorities to the disaster.

Assamaka serves as a major border crossing between Niger and Algeria and lies close to the frontier with Mali. The surrounding desert region is a well-known transit corridor for migrants attempting the dangerous journey from various African countries toward Europe. Many have previously perished in the same scorching sands from thirst or starvation.