South African President Cyril Ramaphosa says there will be an investigation into the 'mysterious' arrival of a chartered plane carrying 153 Palestinians from Gaza into the country.

The group arrived at OR Tambo International Airport but were initially refused entry and were stuck in the plane for more than 10 hours as they 'did not have the customary departure stamps in their passports', local authorities said.

Most were eventually allowed in after intervention from a local charity and because of the government's 'empathy [and] compassion', Ramaphosa said.

The circumstances of their departure from Gaza and travel to South Africa remain unclear.

South Africa has maintained strong support for the Palestinian cause throughout the war between Hamas and Israel in Gaza.

Ramaphosa said the group 'somehow mysteriously were put on a plane that passed by Nairobi' and flew to South Africa, reports the News24 site.

Israeli military body Cogat, which controls Gaza's crossings, said in a statement: 'The residents left the Gaza Strip after Cogat received approval from a third country to receive them.'

According to the Palestinian embassy in South Africa, the group left Israel's Ramon Airport and flew to the country via the Kenyan capital, Nairobi, 'without any prior note or coordination'.

A statement from the embassy said 'an unregistered and misleading organization [had] 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'.

Of the 153, 23 managed to fly on to other destinations, leaving 130 who were admitted into the country, South African authorities say.

Ramaphosa stated that 'we cannot turn them back', emphasizing the humanitarian aspect of the crisis as these individuals come from a war-torn country.

Home Affairs Minister Leon Schreiber clarified the entry policies for Palestinian passport-holders, revealing the initial refusal was based on insufficient travel documentation. Once it was confirmed that their missing documentation did not indicate an intention to seek asylum, they were allowed into South Africa.

Gift of the Givers, a South African charity, has committed to providing accommodation for the group.

Civil societies in South Africa are demanding investigations into the conditions the Palestinians had faced in Gaza and the exact route of the aircraft that transported them.

As one Palestinian expressed upon arrival, 'We came from Gaza where we've faced death on daily basis... and we are lucky to be here.'