What does the notation "1:1 (0:0)" mean for soccer results?

From http://www.fifa.com/worldcup/matches/round=249722/match=300061454/index.html

South Africa and Mexico tied 1–1 in their match. I assume that’s what the 1:1 part means, and that’s fine. What does the (0:0) part mean? There is no overtime or penalty kicks in the Group Stage of the World Cup, so I don’t think it’s that…. what is it?