BEIJING — Authorities in northern China’s coal country this week demolished a well-known Christian mega-church, underscoring long-standing tensions between religious groups and the officially atheistic Communist Party.

Witnesses and overseas activists say paramilitary People’s Armed Police forces used excavators and dynamite on Tuesday to destroy the Golden Lampstand Church in the city of Linfen in Shanxi province.

ChinaAid, a U.S.-based Christian advocacy group, said local authorities planted explosives in an underground worship hall to demolish the building, which was built with nearly $3 million in contributions from local worshippers in one of China’s poorest regions.

The church, with a congregation of more than 50,000, has long clashed with the government. Hundreds of police and hired thugs smashed the church and seized Bibles in an earlier crackdown in 2009 that ended with church leaders receiving long prison sentences.

At the time, church leaders were charged with illegally occupying farmland and disturbing traffic order by getting together, according to state media.

There are an estimated 60 million Christians in China, many of whom worship in independent congregations like the Golden Lampstand. Millions of Christians, Buddhists and Muslims also worship in state-sanctioned assemblies.

But the surging popularity of non-state-approved churches has raised the ire of local authorities, wary of any threats to the party’s rigid political and social control.

Freedom of religion is technically guaranteed under China’s constitution, so local authorities are often seen as using technicalities to attack unregistered churches. Charges of land or building violations and disturbing the peace are among the most common.

The state-run Global Times newspaper, citing an unidentified local official, reported Wednesday the official reason for the demolition was that it did not hold the necessary permits.

Religious groups must register with local religious affairs authorities under Chinese law, the report said. The church was illegally constructed nearly a decade ago in violation of building codes, it said.

Pictures distributed by ChinaAid showed the church’s steeple and cross toppled in a large pile of rubble.

A local pastor at a nearby church, who spoke on condition of anonymity, said he saw large numbers of paramilitary police on Tuesday blanketing the area around the church, which was being taken apart by heavy machinery.

He later heard, but did not witness, a loud explosion, the pastor said.

The Golden Lampstand Church was built by husband and wife evangelists Wang Xiaoguang and Yang Rongli as a permanent home for their followers.

The couple had been preaching around Linfen since 1992, establishing congregations in improvised spaces such as factory dormitories and greenhouses.

While authorities did not block the church’s construction, they later cracked down. The couple and other church leaders were sentenced to prison on charges including illegally occupying agricultural land and assembling a crowd to disrupt traffic.