The escalation of Israeli military violence in Gaza is unacceptable and must stop immediately, said the South African government on Sunday.

"The South African government unequivocally and in the strongest possible terms condemns the escalation of violence on the part of Israel brought about by the launching last night of a ground invasion into Gaza," read a statement issued by the foreign affairs department.

"The resultant loss of life and continuing humanitarian catastrophe in Gaza is unacceptable."

It called on the Israeli government to stop the military onslaught in Gaza and immediately and unconditionally withdraw troops from the area. More lives would be lost if the violence was not stopped.

"The Gaza strip is recognised as one of the most densely populated areas in the world and the Israeli land offensive, involving the use of armoured vehicles and heavily-armed troops, with the close support of artillery and helicopter gunships, will inevitably lead to an even larger loss of civilian life, which will have an impact throughout the region for years to come."

Medical facilities in Gaza already could not cope with the number of people injured from air strikes.

"They will clearly be unable to deal with the increased number of casualties as a result of the land invasion."

South Africa said it called on the United Nations to stand together in condemning the escalation of violence on the part of Israel. The international community should use whatever means possible to stop the violence.

"The South African government calls on all parties to resume negotiations as soon as possible."

In total, more than 485 Palestinians have died since Israel began its offensive in Gaza on December 27, Agence France-Presse reported on Sunday.