For a long time, Pipeline residents have complained that sex workers start operating as early as 8 p.m. and continue until dawn every day. Their preferred area is around Plot 10.

Residents say these twilight girls come from as far as Kayole, and early in the morning, they can be seen boarding matatus to leave the estate. The practice has now spread to AA Estate, which neighbours Imara Daima.

Some years back, churches like the Free Pentecostal Fellowship in Kenya (FPFK) and Glory of Christ fought the menace, albeit spiritually. At one point, FPFK organized a procession in the estate before holding a crusade.

Solomon Mwalili, a pastor at the church, said that the move to save their beloved estate from prostitution was part of a divine mission.

"We want to reclaim Pipeline for Jesus Christ, and we are trying our best by holding crusades in the estate," he said at the time.

"As a church, we have also established Uzima Vocational Training Institute, where these girls can be trained in short courses like dressmaking and hairdressing, among others, to earn a decent living," added Mwalili.

It is believed that the twilight girls prefer Pipeline because the demand for commercial sex is high. In Nairobi, sex workers are often arrested for being a 'nuisance,' as the city by-laws prohibit loitering in the streets for prostitution.

In February 2012, then-Nairobi Mayor George Aladwa, now Makadara MP, attempted to review the by-laws to allow sex workers to operate freely in the capital.

Aladwa revealed that commercial sex workers had requested his office to carve out a section of Koinange Street for them, but his move met resistance from city residents.