More than 90 Somali men and women were held shackled on an airplane for nearly 48 hours – and some were forced to urinate where they sat – during a failed attempt to deport them from the US, according to a lawsuit filed late on Monday.

Seven passengers representing the 92 people onboard alleged they suffered “inhumane conditions and egregious abuse” on the 7 December flight, which was due to land in Mogadishu, Somalia, but only reached Dakar, Senegal, where it was held for 23 hours before returning to the US.

“When the plane’s toilets overfilled with human waste, some of the detainees were left to urinate into bottles or on themselves,” the lawsuit says. “Ice [Immigration and Customs Enforcement] agents wrapped some who protested, or just stood up to ask a question, in full-body restraints. Ice agents kicked, struck, or dragged detainees down the aisle of the plane, and subjected some to verbal abuse and threats.”

Ice does not comment on pending litigation but denied allegations of mistreatment in earlier statements about the flight. The agency said the flight was turned around after a layover in Dakar because the relief crew was unable to get sufficient rest.

“Various logistical options were explored, and ultimately Ice decided to reschedule the mission to Somalia and return to the United States with all 92 detainees,” the agency said in a statement.

The plaintiffs, who include people who have lived in the US for decades, say they fear death and persecution at the hands of the Islamist militant group al-Shabaab, which has spread terror throughout Somalia and killed more than 500 people with a massive truck bomb in October.

This fear has been heightened by widespread media attention their flight received when it returned to the US.

“When this plane goes back, everyone will know they are coming back, including al-Shabaab,” said Rebecca Sharpless, an immigration attorney who helped file the lawsuit.

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In sworn testimonies, the plaintiffs described scenes of violence on the plane and their intense fears of being returned to Somalia, where the US this year deployed its highest number of troops in 25 years as part of a broad offensive against al-Shabaab.

Plaintiff Abdiwali Ahmed Siyad, 33, said he left Somalia in 1990 after being struck by a bullet, losing an eye and being stabbed by a terrorist there when he was four years old.

“An Ice guard stepped on my shackles and palmed my face and shoved me down twice,” Siyad said in a sworn testimony. “The guards also refused to let me pray or use the bathroom.”

He said he was denied medication for depression and used the bathroom once in 48 hours.

In his testimony, Siyad, the father of a US citizen, said that he had no ties to the country after his brother was murdered and his family’s property seized by al-Shabaab. “Because of the press and reporting about this plane incident, I am very, very afraid al-Shabaab will know about me and will murder me if I return,” he said.

Attorneys for the deportees said Ice indicated the group could be returned to Somalia on Wednesday or sooner.

The class action lawsuit asks the US to instead reopen the passengers’ removal cases because of a US law that forbids removal of people to places where they would probably face persecution or torture. The lawsuit also asks the US to treat the passengers for injuries sustained on the flight and ensure that those put back on the path to deportation are not abused by Ice in future removal proceedings.

Before the lawsuit was filed, Ice denied in a statement that anyone was injured on the flight and said the bathrooms were functional during the flight. “The allegations of Ice mistreatment onboard the Somali flight are categorically false,” Ice said.

The agency also said 61 of the 92 passengers had criminal convictions including homicide, rape and aggravated assault. But lawyers for the passengers said some of the convictions were for petty crimes such as shoplifting. “I’m not terribly convinced we’re deporting the worst of worst,” said Minnesota attorney Kim Hunter, who represents two of the passengers.

Hunter said about one-third of the passengers, including her clients, did not have a criminal record. Many passengers were also asylum seekers who had been denied protection even as family and friends received temporary deportation protection.

The US has in recent decades avoided deporting people to Somalia because of its instability – only 31 people were removed to Somalia in fiscal years 2012 and 2013.

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Despite the escalating conflict with al-Shabaab, the US has dramatically increased deportations there since late 2016. In fiscal year 2016, 198 Somalis were deported, rising to 521 in 2017.

The sudden rounding-up of Somali immigrants with long-established ties to their community echoes Ice’s attempt to deport more than 200 Iraqi Christians in June.

A federal judge halted those deportations because of the “extraordinarily grave consequences” detainees could face if returned to Iraq.

“This is now a disturbing pattern where Ice is targeting people who have been living in the community for many years on these orders of supervision and with work permits and suddenly they are snatched from their families and communities,” said Sharpless.