The kidnapping of 23 Korean church volunteers in Afghanistan has raised questions in South Korea over whether the country's evangelical Christian groups may be too zealous in sending missionaries overseas.

|PIC1|There are an estimated 17,000 South Korean Christian missionaries abroad, the largest contingent after those from the United States, with many of them in volatile regions.

Several major dailies questioned why the church that sent the volunteers to Afghanistan ignored government warnings of the risk of conflict with the Islamic militarist Taliban.

"Religious groups should realise once and for all that dangerous missionary and volunteer activities in Islamic countries including Afghanistan not only harm Korea's national objectives, but also put other Koreans under a tremendous amount of duress," the right-leaning Chosun Ilbo newspaper said in an editorial on Monday.

The Saemmul church from which the kidnapped Koreans were dispatched is relatively moderate and its missions abroad have focused on volunteer medical and humanitarian work, people in the Christian community say.

But for many increasingly wealthy evangelical churches in South Korea, dispatching missionaries and Christian volunteers abroad has become a competition, with larger numbers widely considered a gauge of the strength of their beliefs.

"I have never seen this kind of zeal elsewhere," said Song Jae-ryong of Kyunghee University, in Seoul, who specialises in religious sociology.

Critics say that while the churches do a lot of good abroad, they can at times have a shallow view of the world.

"South Korean evangelism has a strong tendency to push for what they believe in, often in disregard of the peculiarities of the places they are trying to work in," Song said.

South Korea has one of the largest percentages of Christians in Asia, at around 30 percent of the population. The religion grew in post-war South Korea, with many seeing it as a way to a better education and social standing.

In some cases, dozens or even hundreds of South Korean evangelicals can be found in a single small city, with some even fighting one another over the voluntary work to be done, the left-leaning daily Hankyoreh reported.

A few evangelical church leaders boast about getting around South Korean government warnings and bans other countries place on missionary visas by unofficially dispatching missionaries.

This practise has drawn criticism among other South Korean churches, because it makes it difficult for locals to distinguish between Christian volunteers doing humanitarian work and those whose primary mission is to seek converts overseas.

Last August, Afghanistan deported hundreds of visiting South Korean Christians who wanted to parade through Kabul over security fears after Islamic clerics demanded their expulsion, accusing them of trying to proselytise.