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." It did not specify the country.

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".

The BBC has asked the Kenyan government for comment.

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

Ramaphosa, speaking during an event in Johannesburg, said he was informed of the unfolding crisis by the home affairs minister.

In response, the president said "we cannot turn them back", according to News24.

"Even though they do not have the necessary documents and papers, these are people from a strife-torn, a war-torn country."

The president also told reporters the South African government would carry out a "proper evaluation" of the matter and update the public on "what is happening and how this matter came to be where it is", according to public broadcaster SABC.

Home Affairs Minister Leon Schreiber said that while Palestinian passport-holders qualified for 90-day visa-exempt access to South Africa, the lack of departure stamps, return tickets or accommodation addresses in some of the travellers' documentation resulted in the initial refusal to let them into the country.

Once it was established that the absence of this information "did not indicate that the travellers wished to apply for asylum" and their accommodation was confirmed, they were granted entry.

"All of the travellers are in possession of valid passports and, at present, none of them have applied for asylum," he said.

South African charity Gift of the Givers has said it will provide the group with accommodation in the country.

Civil societies in South Africa have called for investigations into the conditions the Palestinians had fled in Gaza and the exact route of the aircraft.

One of the Palestinians who spoke to local eNCA TV expressed his relief to be in South Africa, describing it as a country of "peace, laws and justice".

"We came from Gaza where we've faced death on daily basis. We have survived a war of two years and we are lucky to be here," said one man who had fled with his wife and two children.

Gift of the Givers has since called for Ramaphosa to investigate the home affairs ministry and border authority for the "humiliation they've caused" the Palestinians.

The organisation's founder Dr Imtiaz Sooliman said this treatment included being forced to wait for hours on the tarmac at the airport, being denied food provided by the group and "using every excuse in the book to prevent these passengers from disembarking".

South Africa has been highly critical of Israel's military operation in Gaza.

The country's sympathy for the Palestinian fight for an independent state goes back decades, particularly the early 1990s when anti-apartheid icon Nelson Mandela pledged support for the Palestinian cause.

Large pro-Palestinian marches have been held around South Africa since the conflict began.

Smaller pro-Israel marches and rallies have been held in the country, which hosts the largest Jewish community in sub-Saharan Africa.

In 2023, the South African government filed a case against Israel with the International Court of Justice, accusing it of genocide in Gaza. Israel has strongly rejected the South African claim, calling it "baseless".