"A truck driver appeared to have lost control of his vehicle when he was overtaking," Barnes said in a statement on Wednesday.
"He came straight at us and collided with our bus and although, we did not get hurt, our police escorts were seriously hurt when the truck slid and hit them.
"I want to assure everybody back home that we are fine and the match will go on as planned."
The accident took place on Tuesday when the tourists were headed to the central town of Dambulla to play a four-day 'Test' against the Sri Lanka 'A' team which began on Wednesday.
The South Africans, led by Test star Jacques Rudolph, will also take part in a one-day tri-series against the 'A' teams of Sri Lanka and New Zealand in Colombo from September 21-October 1.