Christian protesters in China have camped out for a month on the roof of their church to stop authorities from taking down its cross, defying calls from officials to give up their campaign, congregation members said on Thursday.

Communist China officially guarantees freedom of religion though authorities are sometimes suspicious of religious groups.

Christians in Zhejiang province, which has a growing Christian population, say authorities have been taking downcrosses on churches since last year.

Twenty-two Christians from the Ya Village Church in the Zhejiang city of Huzhou have been camping out overnight on the church roof since early July, threatening to jump off if a government order to remove the cross is carried out, said two church members, Zhang Chaoxia, and a man surnamed You.

Zhang said eight Christian protesters were still on the roof on Thursday, others having left because of sickness and the heat. Officials had urged them to give up and leave, threatening them with jail if they refused, Zhang said.

"We've heard that tonight, the government is going to dismantle our cross," Zhang said by telephone from the roof. "Our hearts are determined not to let them forcibly demolish our cross.

"We'll use extreme measures to protect our cross. We've been forced to take this path."

The state-run Global Times newspaper said in July authorities in Zhejiang had denied demolishing crosses on churches, but had said some crosses had been "relocated" out of safety concerns.

The newspaper said on Wednesday that crosses on churches in Zhejiang violated building regulations.

This week, police detained seven members of another church in the province for suspected crimes including embezzlement, state media and a lawyer said, after they resisted a bid to take down their cross.

Zhang said security forces had surrounded her church, preventing supporters from bringing supplies.

Government and police officials in Huzhou did not answer repeated calls for comment. The Zhejiang governmentdid not respond to a request for comment.

Photographs from activists distributed online showed church members surrounding the cross on the roof. Reuters could not independently verify the photographs.

On Tuesday, government officials told church members that the cross would be taken down without giving them a reason, said You, who declined to give his full name.

In recent weeks, rights activists have reported a spike in cross removals in Zhejiang. As of the end of June, more than 1,500 churches had their crosses demolished or removed in the province, according to China Aid, a Texas-based Christian advocacy group.