South Africa will abandon their tour of Sri Lanka on the strength of a report by an independent security consultant, Cricket South Africa (CSA) said on Wednesday.
The report found that "the current risk to the team is at an unacceptable level", a CSA media release said.
"In the light of this independent report by the Olive Group, who were appointed at the behest of the International Cricket Council (ICC), we have no alternative but to bring the team home as soon as possible," the release quoted CSA chief executive Gerald Majola as saying.
Members of the team management and players were seen settling their hotel bills on Wednesday and attempting to change their flights in the team's Colombo hotel.
The pullout follows a car bomb blast that killed seven people near the team's hotel on Monday.
South Africa, who lost the Test series to Sri Lanka, were to have played in a triangular series with the hosts and India.
Sri Lankan cricket authorities had tried to rescue the tournament by beefing up security, guaranteeing the team traffic-free roads for venue transfers, armed escorts and personal bodyguards.
CSA announced on Tuesday that the team would stay while the new security measures were evaluated following a request from the ICC for an independent review by a Dubai-based private security firm.
The evaluation was completed on Wednesday and sent to CSA.
India will now play Sri Lanka in a three-match one-day series scheduled on August 18, 20 and 22.