Algeria has denied mistreating migrants amid claims it has abandoned more than 13,000 in the Sahara Desert over the past 14 months, including pregnant women and children.

The country has reportedly expelled the migrants without food or water and forced them to walk, sometimes at gunpoint, in the intense heat.

Video shows people walking by the hundreds in temperatures that Associated Press, who obtained the recording, said reached 48C.

In Niger, where the majority head, the lucky ones limp across a desolate 10-mile no man’s land to the border village of Assamakka.

Others are reported to have wandered for days before a UN rescue squad found them.

Untold numbers have died, with nearly all of the survivors interviewed by AP telling of how people in their groups simply vanished in the desert.

“Women were lying dead, men... other people go missing in the desert because they don’t know the way,” says Janet Kamara, who was pregnant at the time. “Everybody was just on their own.”

She recalled at least two nights in the open before her group was rescued, but said she lost track of time.

“I lost my son, my child,” says Ms Kamara, who is Liberian.

Another woman in her early twenties also went into labour and lost her baby, she says.

Algeria’s mass expulsions have picked up since October 2017, as the European Union renewed pressure on North African countries to head off migrants going north to Europe via the Mediterranean Sea or the barrier fences with Spain.

An EU spokesman said he was aware of what Algeria was doing, but that “sovereign countries” can expel migrants as long as they comply with international law.

Unlike Niger, Algeria takes none of the EU money intended to help with the migration crisis, although it did receive $111.3m (£84m) in aid from Europe between 2014 and 2017.

Algeria provides no figures for its involuntary expulsions, but the number of people crossing on foot to Niger has been increasing since the International Organisation for Migration started counting in May 2017 to as high as 2,888 in April 2018.

In all, according to the IOM, a total of 11,276 men, women and children survived the march.

At least another 2,500 were forced on a similar trek into neighbouring Mali, with an unknown number succumbing along the way.

The migrants AP talked to described being rounded up hundreds at a time, crammed into trucks for hours to what is known as Point Zero, then dropped in the desert and pointed towards Niger.

“There were people who couldn’t take it. They sat down and we left them. They were suffering too much,” said Aliou Kande, an 18-year-old from Senegal.

Mr Kande said nearly a dozen people gave up, collapsing in the sand. His group of 1,000 wandered from 8am until 7pm. He never saw the missing people again.

“They tossed us into the desert, without our telephones, without money,” he says.

The migrants’ accounts are confirmed by videos collected by AP over months, which show hundreds of people stumbling away from lines of trucks and buses, spreading wider and wider through the desert.

Liberian Ju Dennis filmed his deportation with a phone he kept hidden. It shows people crammed on the floor of an open truck, trying to shade their bodies from the sun.

“You’re facing deportation in Algeria – there is no mercy,” he says. “I want to expose them now... we are here, and we saw what they did – and we have proof.”

Migrants arrive in Spain after being turned away from Italy and Malta

Algerian authorities refused to comment. But Algeria has in the past denied criticism that it is committing rights abuses by abandoning migrants in the desert, calling the allegations a “malicious campaign” intended to inflame neighbouring countries.

The Sahara is a swift killer that leaves little evidence behind. The International Organisation for Migration has estimated that for every migrant known to have died crossing the Mediterranean, as many as two are lost in the desert – potentially upwards of 30,000 people since 2014.

The vast flow of migrants puts an enormous strain on all the points along the route.

“They come by the thousands. This time, the expulsions that I’m seeing, I’ve never seen anything like it,” said Alhoussan Adouwal, an IOM official who has taken up residence in Assamakka to send out the alert when a new group arrives.

He then tries to arrange rescue for those still in the desert. “It’s a catastrophe,” he says.

Most choose to leave by IOM bus for the town of Arlit, about six hours to the south through soft sand, and on to Agadez, a city in Niger that has been a crossroads for African trade and migration for generations.

Ultimately, they will return to their home countries on IOM-sponsored flights.