A Christian human rights group is concerned for the welfare of hundreds of refugees forcibly repatriated from China to North Korea.

Christian Solidarity Worldwide (CSW) said that over 500 were sent back this week and are now at risk of being tortured, imprisoned or publicly executed.

The organisation said that anyone who might have been in contact with Christians is especially at risk.

"Those found to have had contact with Christians are known to face particularly harsh punishment," CSW said.

Radio Free Asia reports that most of the refugees sent back were civilians and religious figures who were arrested while trying to reach South Korea via China.

CSW's Founder President Mervyn Thomas condemned their repatriation to North Korea, a closed-off communist country with one of the worst human rights records in the world.

"The horrific treatment they will now face in North Korea is no secret, and it is unacceptable that China persists with this policy which is in contravention of international law," he said.

Mr Thomas appealed to North Korea not to punish the repatriated refugees and urged the international community to do more to hold the country accountable.

"We call on North Korean regime to uphold and respect human rights, to release all those currently detained in prison camps immediately and unconditionally, and to ensure that those who have been forcibly returned to the country do not face punishment," he said.

"Furthermore, we urge states to strengthen measures to hold the North Korean regime to account, so that these calls become a reality."