A purported Taliban spokesman, Qari Mohammad Yousef Ahmadi, has said the deadline had been extented by three hours.
The militants on July 29 warned the Afghan government to release some of its captured fighters or the hostages will die. The militants set a deadline of 0730 UTC/GMT today for the release of the fighters.
A leader of the South Korean group was shot and killed last week.
Afghan officials today asked the Taliban to extend a deadline for the lives of 22 South Koreans, including many women.
Merajuddin Pattan, the governor of Ghazni Province, where the South Koreans were kidnapped on July 19, said that the authorities talked to the Taliban after they set the deadline and asked for two more days of talks.
"We have seriously asked the Taliban side that the Korean women should be released unconditionally because it's a great dishonor for the Afghan tradition," Pattan said. "In our history, people never took [women] hostage. I believe this will be a black scar on the face of the Afghan honor."
There was no immediate comment from the Taliban on Pattan's extension demand.
The rebels earlier set four other deadlines, but they expired without incident.