Chinese officials detained a pastor, her daughter, and her three-year-son after the family refused to stop carrying out mission work -- and their exact whereabouts remain unknown.

According to persecution watchdog China Aid, officials seized Pastor Xu Shizhen, her daughter, Xu Yuqing, and Xu Yuqing's three-year-old son, Xu Shouwang, on September 22 after the two women took part in Zion Church's efforts to spread the Gospel in local public parks and squares.

The women sang, danced, performed with bamboo instruments, and preached during these events, even though the local religious affairs, public security, and national security bureaus frequently interrupted and attempted to shut them down.

The three remain detained, and family members are unsure of whether they are under criminal or administrative detention. Police reportedly informed them they had separated the women from the child, keeping him at the station while transferring his grandmother and mother to other facilities.

Calls to the police station and Yang Haijun, the deputy director of the Xianan District Religious Affairs Bureau who spearheaded the persecution of Zion Church, have been unsuccessful, according to China Aid.

Pastor Xu has previously been targeted by Chinese authorities; last month, she, along with members of her congregation, was driven from a public square while attempting to preach. A short time earlier, the religious affairs bureau sent her a notice accusing the church of violating the Regulations on Religious Affairs and ordered her to stop the missionary work.

Previously, she pastored Hongqiao Church, a house church that was acquisitioned by the government-regulated Three-Self Church in April 2012 after officials forcibly occupied its building and damaged church property. Xu Shizhen left the church and founded a new one, but the police continued to harass them for their work.

Last month, communist officials issued "notices" to over a hundred churches in Wenzhou, known as "China's Jerusalem," informing Christians that children are no longer permitted to enter any church.

"Many Sunday schools in Wenzhou were shut down," a Wenzhou Christian identified only as Li told China Aid. "Many teachers sent messages to their colleagues in group chats in order to prevent children from attending religious gatherings."

School teachers were also banned from attending church; the Yonglin district instructed schools that "the higher authorities strictly forbid all secondary and primary school teachers, students and toddlers to join Catholic or Protestant churches."

The new regulations were set in place to ensure children develop "a correct worldview and set of values," according to the Ouhai district's notice.

"Minors receiving religious education and formation too early in churches would seriously affect the normal implementation of the education system," it said.

Government inspectors will "launch open and undercover investigations" on Sundays in both state-sanctioned churches and underground communities to enforce the ban, authorities warned.

Because of these ongoing abuses, China is ranked 39th on Open Door USA's World Watch List of countries where Christians face the most persecution.