House churches across China have been hit by a wave of arrests and detentions, says China Aid Association (CAA), the leading support group for China's persecuted Christians.

CAA said that the sudden increase in incidents throughout May involving the Religious Affairs Bureau and the Public Security Bureau is "indicative of a crackdown".

House church meetings have been disbanded and a number of Christians have been arrested, including two Christians in Xinjiang province who were charged with being "separatists". Throughout the province, officials have posted signs asking citizens to report any "evil cult activity", a label which encompasses house churches.

In Hebei province, officials closed down a Bible school on May 13, while on May 15 Public Security Bureau officials broke up a prayer meeting held by more than 20 Christians for victims of the earthquake and for the Olympics.

CAA said that Chinese government officials had turned away and also arrested some house church members who had volunteered to help victims of the devastating May 12 earthquake in Sichuan province.

It compared the behaviour of the Chinese Government to that of the Burma military junta in initially refusing international aid.

"Such biased behaviour is a reminder of the irrational prejudice the CPC [Communist Party of China] holds against house church members who want nothing more than to have true religious freedom and help their fellow countrymen in this hour of need," the group said.

CAA asked for prayers and aid from churches around the world in the wake of the earthquake, and said it was actively working with the Chinese house churches to bring relief items to survivors.