Five people deported from the United States refused to leave the aircraft after it landed in Liberia on Thursday, forcing U.S. authorities to divert them to Equatorial Guinea in an early test of Washington’s new deportation agreement with Monrovia.

The incident occurred when the flight arrived at Roberts International Airport near Monrovia on August 20 with 20 deportees—the first group under a deal that could send up to 1,200 third-country nationals to Liberia over 12 months.

According to a Liberian official who spoke to Reuters on condition of anonymity, only 15 passengers disembarked.

The five who remained on board included three Cuban men, a Brazilian man and a Cameroonian woman. Three of the men identified themselves as Carlos Rodriguez Lopez, Darwin Hernandez and Emilio Destrade Correoso.

Speaking in Spanish to The New York Times, they described U.S. federal agents placing knees on their necks as they resisted removal.

Authorities told the migrants they would be returned to the United States. Instead, the aircraft flew to Malabo, Equatorial Guinea’s capital, where they were forced to disembark against their will. Flight data from Human Rights First’s ICE Flight Monitor showed the plane departed Louisiana, stopped in Dakar, arrived in Monrovia at 12:45 p.m., and reached Malabo at 8:50 p.m. local time.

“We thought they were trafficking us like they traffic people in other countries,” Rodriguez Lopez told The New York Times. He said four officers restrained him at once in Liberia.

The five are now detained with about 40 other US deportees at a decommissioned hotel in Malabo. In a joint statement on August 12, five rights groups—including Asian Americans Advancing Justice-Atlanta and EG Justice—alleged that some deportees at the facility had experienced arbitrary detention, physical abuse, threats, inadequate medical treatment and restricted access to lawyers.

“What happened here, a large group refusing removal on one end and then being moved onward to yet another country, is highly unusual,” said Claire Trickler-McNulty, a former senior adviser at U.S. Immigration and Customs Enforcement.

The State Department said Friday it remained “unwavering in our commitment to end illegal and mass immigration and bolster America's border security”. A Department of Homeland Security spokesperson said all migrants “were deported to a safe third country,” adding: “If a judge finds an illegal alien has no right to be in this country, we are going to remove them. Period”.

“The Trump Administration is using these deportation agreements to shuffle people around to different countries like objects,” said Meredyth Yoon, litigation director for Asian Americans Advancing Justice-Atlanta.