(Adds arrival of hostages to Dubai)
By Simon Gardner
KABUL, Aug 31 (Reuters) - Nineteen newly-freed South Korean hostages headed home on Friday after a six-week kidnap drama in Afghanistan following a deal with Taliban insurgents critics fear could spur more abductions.
The South Korean Christian volunteers, part of a group of 23 missionaries kidnapped in southeast Afghanistan in mid-July, arrived in Dubai on a chartered United Nations plane from Kabul, airport and security officials in Dubai said.
They are expected to spend the night in the Gulf Arab city before leaving on Saturday for Seoul.
The Taliban killed two male hostages, while two women released earlier as a goodwill gesture have already flown home. The insurgents however have vowed to abduct more foreigners.
Some of the released hostages told a small pool of South Korean media in Kabul on Friday they lived in constant fear for their lives and were split up into small groups and shuttled around the Afghan countryside to avoid detection.
One Taliban member would tend to a farm by day and then grab a rifle and stand guard over hostages at night.
"At the beginning I had writing supplies so I kept a diary, but the Taliban kept searching us and took them away," Seo Myung-hwa, 27, was quoted by South Korea’s Yonhap news agency as saying.
"Fortunately I was wearing white trousers, so I rolled them up and started writing on July 24." Another freed hostage apologised to South Korea’s government and people for causing trouble.
Foreign media was barred from talking to the hostages in line with South Korean government policy.
The last batch of hostages released to the Red Cross outside Ghazni town late on Thursday looked pale, the women covering their faces with scarves. However, Afghan officials said they were in good health.
The kidnapping was the largest in the resurgent Taliban campaign against foreign forces since U.S.-led troops ousted the Islamists from power in 2001.
The Taliban decided to free the hostages after Seoul agreed to pull all its nationals out of the central Asian country.
Some Afghan officials say South Korea also agreed to pay a ransom during negotiations with the Taliban, which one foreign diplomat said started out as a demand for $20 million, an allegation the Korean government has denied.
Critics say negotiating with the Taliban sets a dangerous precedent and could spur more abductions.
In Washington, the United States welcomed the release of the hostages but strongly condemned the Taliban for taking them in the first place.
"We hope that this firmly brings to a conclusion this incident and that there will not be similar ones that occur in the future," said State Department spokesman Tom Casey.
In New York overnight, U.N. Secretary-General Ban Ki-moon was "deeply concerned for the safety and welfare of the other nationals who are being held against their will in Afghanistan", including a German and four Afghans, a spokeswoman said.
Taliban fighters seized two German aid workers and five Afghan colleagues in a separate incident in mid-July in Wardak province, southwest of the capital Kabul. They killed one German. One Afghan escaped.
"To those Taliban who were responsible for this crime, I say shame on you," Tom Koenigs, Ban’s special representative for Afghanistan, said in a statement. "What honour is there in kidnapping and mistreating women, and so many of them?"
South Korea had already decided before the crisis to pull its 200 engineers and medical staff out of Afghanistan by the end of this year. Since the hostages were taken, it has banned its nationals from travelling there.
The freed hostages are expected to face a cool reception at home. Some South Koreans say the group are partly to blame after they ignored their government’s own advice not to travel to areas where the Taliban are active. (Additional by Hamid Shalizi in KABUL, Jack Kim in SEOUL and Evelyn Leopold at the United Nations and Dina al-Wakeel in Dubai)