He says a team of wildlife rangers tracking the lions aims to capture them and return them to the park.
KWS has cautioned people living in Lang’ata and Kibera to be vigilant as the lions are very risky and warned the public against harming the animals.
Nairobi’s skyscrapers can be seen from the park.
A Kenya Wildlife Service (KWS) officer carries a tranquilizer gun, during a search Friday for lions who left Nairobi’s national park and went into highly populated areas.
The Kenya Wildlife Service tweeted that six lions wandered into residential areas, but a spokesman for the agency said the number is unclear.
Local media reported as many as six lions might be on the loose.
The big cats find themselves under growing pressure as one of Africa’s fastest growing cities creeps onto ancient migration routes and hunting grounds. Escaped lions are sometimes killed by livestock farmers protecting their herds. “We responded immediately. But we have not been able to track them down”.
“We were called at 4 a.m. and told that some two lionesses, we believe, including the new mother, had been seen on the road near Langata Hospital”, spokesman Paul Udoto told the newspaper.
It is estimated about 30 lions live in the park. Conservationists have opposed the railway line, saying it will further damage wildlife habitat.