More than 600 people have been forcibly deported from Libya on a “dangerous and traumatising” journey across the Sahara, in what is thought to be one of the largest expulsions from the north African country to date.

The International Organisation for Migration (IOM) confirmed 613 people, all Nigerien nationals, arrived in the desert town of Dirkou in Niger last weekend in a convoy of trucks. They were among a large number of migrant workers rounded up by the authorities in Libya over the past month.