In Beijing, police have detained dozens of churchgoers and leaders of Early Rain Church in Chengdu, one of China's most prominent Protestant ‘house’ churches, in the latest government action against unregistered religious groups. Members of the church have been unable to contact pastor Wang Yi, the church's founder, or his wife, and church groups on the instant messaging platform WeChat have also been blocked. China's constitution guarantees religious freedom, but since President Xi Jinping took office six years ago, the government has tightened restrictions on religions seen as a challenge to the authority of the ruling Communist Party. The law requires that all places of worship register and submit to government oversight, but some churches have declined to register, for various reasons.