Her son had killed a pastor, but instead of anger, the pastor's congregation showered her with love and forgiveness.

Overwhelmed by the show of Christian virtues, the unidentified woman from Vietnam embraced Jesus Christ, the Gospel Herald reported, citing a source from the Christian Aid Mission (CAM).

"She saw the love of the people towards her, and so she believed in Christ," the Christian ministry director based in Vietnam's Nghe An province said.

The woman's son, also unidentified, was reportedly the driver of a car that fatally ran over the pastor of a local ministry in an incident that happened last year, CAM said.

Another astonishing development happened following the death of the pastor, the unnamed ministry director revealed.

He said the director of another ministry in the region went to the pastor's congregation to offer his condolences. When he asked them if anyone was interested in serving as a replacement for the late pastor, 30 men raised their hands and volunteered to serve the Lord in a region in Vietnam where residents have shown resistance to the Gospel.

Because of the congregants' eagerness to pursue what the fallen pastor started, there are now 12 other churches in the area, the ministry director revealed.

Vietnam ranks 17th on this year's Open Doors USA's World Watch List of 50 top Christian persecuting countries, up three spots from the 2016 list. Christians account for just 9.5 percent of the country's population of 92.7 million.

Vietnam saw a rise in religious freedom violations last year, according to persecution watchdog International Christian Concern (ICC).

It said Catholic and Protestant groups and even members of unrecognised forms of Buddhism were barred from attending services. Government agents brutally attacked Christians and removed the crosses from their churches, it added.

The report was backed up by the Vietnam-based Association to Protect Freedom of Religion, which also noted an increased level of harassment by the authorities on Christians.

"The instances of religious persecution got increasingly worse," Father Anthony Le Ngoc Thanh, head of the association, told Uca News.

He said authorities coerced religious leaders into giving up church property, and prevented Christians from attending services, even during last Christmas.