The body of a second South Korean hostage shot dead by the Taliban in Afghanistan has been found dumped at the side of a road. Taliban kidnappers say they will kill more of the 21 they are holding if demands for the release of prisoners are not met by 0730GMT Wednesday. The Taliban is threatening to kill more of the South Korean hostages it is holding if their demands aren't met by 0730GMT on Wednesday (August 1). The warning came just hours after they shot dead a second hostage. In a phone call to Reuters, Taliban spokesman Qari Mohammad Yousuf said if the Afghan and South Korean authorities don't give a "positive" reply to their demands for Taliban prisoners to be released, they'll start shooting other hostages. On Tuesday (July 31) Afghan authorities recovered the body of a second South Korean killed by his Taliban kidnappers. His blood-stained body was dumped in a field beside a road in Arzoo, a village some 10 km (6 miles) from the eastern city of Ghazni. The South Korean government identified the victim as Shim Sung-min, a 29 year-old former IT firm employee who did volunteer work to help the poor. The Taliban seized 23 Korean Christians, 18 of whom are women, from a bus in Ghazni on the main highway south from the capital, Kabul nearly two weeks ago. They have demanded Taliban rebels imprisoned by the government be freed to secure the safety of the rest of the group of aid workers. Afghan MPs condemned the killings but said they were against a prisoner swap. Foreign Ministry spokesman Cho Hee-Yong said the South Korean government could not suppress its anger. The kidnappers murdered their hostage, he said, without any justification and while the South Korean government was doing its best to resolve the situation. Seoul sent an envoy to Afghanistan last week to step up efforts to free the hostages but analysts say Seoul has few people with expertise in the region and almost no experience in negotiating with the Taliban. Many relatives of the kidnapped Koreans have assembled in the Saemmul Church in Bundang, which supported the ill-fated trip to Afghanistan. Shim Chin-Pyo, father of the second murdered hostage Shim Sung-min, said his world has been turned upside down. He thought his son was alive and "quite well" but within ten hours that was all changed. And he had a message for the Taliban: "Human beings cannot do this. Their behaviour is worse than beasts". Anti-war activists staged a protest in Seoul calling on South Korean troops to be withdrawn from Afghanistan.