An influential Protestant church in China says prominent leaders were arrested in what appears to be a growing crackdown on the underground church movement.

Nine people were detained on Tuesday after police raided their homes and the church office in Chengdu, the Early Rain Covenant Church said. Five of them had been released by Wednesday.

More than 1,000 miles away in Wenzhou, authorities began demolishing the Yayang Church building, as seen in video obtained by the non-profit ChinaAid, which monitors religious persecution.

This latest wave of arrests, after others last year, shows the Communist Party's resolve to snuff out churches that do not align with its ideology, Christian groups say.

The BBC has contacted China's embassy in the UK for comment. Authorities have not made any statements about the arrests, or the demolition in Wenzhou.

China promotes atheism and controls religion. The government said in 2018 there are 44 million Christians in the country, but it's unclear if that number includes those who attend the many underground churches.

The Party has long pressured Christians to join only state-sanctioned churches led by government-approved pastors. However, Christian groups say the grip has tightened noticeably, with arrests becoming more common and prompt.

Just weeks ago, Li Yingqiang, the current leader of the Early Rain Covenant Church, had said he sensed a storm gathering and referred to the imminent prospect of... another large-scale crackdown.

In Wenzhou, local authorities brought in bulldozers, cranes, and heavy machinery earlier this week, starting to take down part of the Yayang Church building. Hundreds of armed and special police officers were deployed to stand guard outside the building.

This current wave of repression reflects the government's determination to stamp out Christian churches entirely, unless they are indoctrinated into the Party's ideology. The situation remains tense as the Early Rain Covenant Church seeks prayers for its members' safety and perseverance in faith.