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.

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