South Africa’s intelligence services are investigating who was behind a chartered plane that landed in Johannesburg with more than 150 Palestinians from war-ravaged Gaza who did not have proper travel documents and were held onboard on the tarmac for around 12 hours as a result, the country’s president said Friday.

The plane landed Thursday morning at O.R. Tambo International Airport, but passengers were not allowed to disembark until late that night after immigration interviews with the Palestinians found they could not say where or how long they were staying in South Africa, South Africa’s border agency said.

It said the Palestinians also did not have exit stamps or slips that would normally be issued by Israeli authorities to people leaving Gaza.

The actions of South African authorities in initially refusing to allow the passengers off the plane provoked fierce criticism from non-governmental organizations, who said the 153 Palestinians — who included families with children and one woman who is nine months pregnant — were kept in dire conditions on the plane, which was extremely hot and had no food or water.

South African President Cyril Ramaphosa said there was an investigation to uncover how the Palestinians came to South Africa via a stopover in Nairobi, Kenya.

“These are people from Gaza who somehow mysteriously were put on a plane that passed by Nairobi and came here,” Ramaphosa said.

Palestinians being ‘exploited’

The Palestinian Embassy in South Africa said in a statement the flight was arranged by “an unregistered and misleading organization that exploited the tragic humanitarian conditions of our people in Gaza, deceived families, collected money from them, and facilitated their travel in an irregular and irresponsible manner. This entity later attempted to disown any responsibility once complications arose.”

It didn’t name who chartered the flight, but an Israeli military official, speaking anonymously to discuss confidential information, said an organization called Al-Majd arranged the transport of about 150 Palestinians from Gaza to South Africa.

The official said that Israel escorted buses organized by Al-Majd that brought Palestinians from a meeting point in the Gaza Strip to the Kerem Shalom crossing. Then buses from Al-Majd picked the Palestinians up and brought them to Ramon airport in Israel, where they were flown out of the country.

South African authorities said 23 of the Palestinians had traveled onwards to other countries, without naming those countries, but 130 remained and were allowed in after intervention from South Africa’s Ministry of Home Affairs and an offer by an NGO called Gift of the Givers to accommodate them.

“Even though they do not have the necessary documents and papers, these are people from a strife-torn, a war-torn country, and out of compassion, out of empathy, we must receive them and be able to deal with the situation that they are facing,” Ramaphosa said.