Two foreigners from the Red Cross who helped free a group of South Korean captives last month have been kidnapped in Afghanistan after talking with militants about the release of a German hostage, officials said Thursday.

An Afghan official said the two foreigners from the International Committee of the Red Cross had gone with their two Afghan drivers to Wardak province in central Afghanistan to discuss the German man, who was kidnapped in July.

All four ICRC staff were taken captive Wednesday afternoon, the official said on condition of anonymity because of the sensitivity of the situation. The two foreigners had helped coordinate negotiations and the release of 19 South Korean captives late last month, the official said.

Ewaz Muslimyar, the police chief of Wardak province, confirmed the two foreigners were abducted in Salar district.

Amid soaring violence in Afghanistan, the number of kidnappings has spiked this year after the Taliban secured the release of five insurgent prisoners in exchange for a captive Italian journalist in March. Critics of the swap said it would encourage more abductions.

The South Korean hostage crisis was another windfall for Taliban militants, winning them face-to-face talks with South Korean government delegates.

Militants kidnapped 23 South Koreans July 19 in Ghazni province as they traveled by bus on a dangerous road from Kabul to volatile Kandahar in the south. Two hostages were killed; the rest were released after weeks of negotiations between the Taliban and the Korean delegation.

The talks were held at the ICRC office in Ghazni, and ICRC officials drove to pick up the South Koreans after they were released.

The German engineer, Rudolf Blechschmidt, was abducted one day before the Koreans. It is believed that he was initially taken by criminals in Wardak, then later handed over to the Taliban.

Blechschmidt is one of two German engineers and five Afghans who were snatched together. The other German was found dead of gunshot wounds on July 21, while one of the Afghans managed to escape.