Christian groups in South Korea, the second biggest supplier of missionaries to the world after the United States, are scaling back operations in trouble spots following the hostage crisis in Afghanistan.

|PIC1|The kidnapping of 23 Korean church volunteers by Taliban insurgents more than two weeks ago has sparked accusations that some Christians are putting proselytizing before common sense.

The kidnappers have already killed two of their hostages and are threatening to kill more unless the Afghan government release Taliban prisoners in exchange - which Kabul authorities have refused to do.

"Our church had about 10 people in Afghanistan," a missionary with one major church in Seoul said. "Most of them are back."

He requested that neither he nor his church be identified because of the sensitivity of the continuing hostage crisis and the "very harsh" criticism at home of missionary work.

An official with another Seoul church, which has focused its missionary work in a number of troubled regions, said its missionaries in Afghanistan would be recalled under a new government guideline that bans all travel to the country.

South Korea has now listed Afghanistan, with Somalia and Iraq, as countries where travel except for official purposes is a punishable offence.

A pastor with the church, also requesting anonymity, said: "For now, there is no plan to send any more."

Missionary groups said they were scaling back short-term programmes - which usually peak in the summer - in conflict zones following the hostage crisis.

There are about 17,000 South Korean Christian missionaries abroad according to official statistics, the largest contingent after the United States, with many of them in volatile regions.

But an official with one national mission federation said the actual number was much bigger.

Relatives of the kidnapped Koreans, who include nurses and English teachers, say their Afghan trip was focused on aid work and they were not trying to convert people in the staunchly Muslim nation.

But the pastor of the Presbyterian Salrim Church, Choi Hyung-muk, said South Korean evangelical churches needed to think hard about aggressively pushing religious teachings "in complete disregard of what the people who they are helping need or want.

"In so many of the cases, there is the element of self-justification, of trying to show off, 'Hey, this is the great work we're doing.'"

Others disagree. Song Kang-ho of The Frontiers, a Seoul-based group that did suspend short-term projects in hotspots after the kidnapping, said their work will continue.

"There is no place in conflict zones for frivolous and irresponsible short-term missions," he said. "Since when was missionary work so safe and always so well-received by the locals?"