Story highlights $4.7 million landmark church has been demolished in China

Officials responsible for demolition say church was an illegal structure

Christian rights group says demolition signals an official anti-religious campaign

A massive church was razed to the ground this week in Wenzhou, a coastal Chinese city nicknamed the "Jerusalem of the East" for its large Christian population.

Local officials responsible for the demolition say the church was an illegal structure that was four times the permitted structure size. But Christian groups are concerned that the demolition signals an official campaign against religious organizations.

The Sanjiang Church took 12 years and 30 million yuan ($4.7 million) to build, reports Chinese media . Its soaring spires were a symbol of worship in a city that is fifteen percent Christian

The church's demolition on Monday was preceded by a month-long standoff between supporters of the church and local authorities, with supporters occupying the church to protest its destruction.

The church was originally a government-approved project under the official "Three-Self Patriotic Movement," a state-sanctioned Protestant church. Last September it was lauded by the local government as a model engineering project.

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But the official rhetoric has since changed entirely.

Jin Leibo, a spokesperson from the propaganda department of Yongjia County, where Sanjiang Church was located, told CNN that the church was destroyed as it was "illegal."

"The building area should be within 1,881 square meters, but they built 7,928 square meters illegally," Jin said. The church was asked to "self-rectify" by April 22, but workers only managed to tear down 500 square meters by deadline, according to officials.

By Monday evening the church had been flattened by bulldozers.

Five local government officials are currently under investigation in relation to the illegal construction of the church, according to Jin. One official was arrested, and another is in custody.

Representatives of the church could not be reached for comment by CNN.

U.S.-based Christian rights group China Aid says the faithful are worried that the church demolition could be a sign that the government is tightening its grip over the spread of Christianity in China.

The organization claims that churches in different parts of Wenzhou and Hangzhou are currently "facing persecution" as a result of a provincial campaign against religious structures that was set into motion after Zhejiang Party Secretary Xia Baolong visited churches across the province and deemed them "too conspicuous."