(CNN) — A group of lions escaped from a park in the Kenyan capital of Nairobi, leaving residents on edge and officials scrambling to find them.

Wildlife officials appeared to have no idea how many of the big cats sneaked out of the park Friday morning.

The Kenya Wildlife Service tweeted that six lions wandered into residential areas, but a spokesman for the agency said the number is unclear.

“We are depending on the public to report if they sight them,” Kenya Wildlife Service spokesman Paul Udoto told the Daily Nation.

Predawn search

The animals escaped from the Nairobi National Park, which is near the central business district. The park is surrounded by an electric fence to keep the animals within its confines. It’s unclear how they got out.

Animals at the park include leopards, buffaloes and giraffes grazing in open spaces with the city’s skyscrapers in the background.

Officials urged vigilance and warned residents to call a toll free number if they spot the big cats.

“Our team has been on ground since 3 a.m. to ensure that the … lions are safely back,” the Kenya Wildlife Service tweeted.

Lioness and cubs

A caller told wildlife officials that the animals were last seen near a hospital in Nairobi, according to Udoto. The caller said the animals included a lioness and cubs.

“We responded immediately,” he told the newspaper. “But we have not been able to track them down.”

Others have called to say they’ve seen the lions in crowded residential areas, he said.

The-CNN-Wire ™ & © 2016 Cable News Network, Inc., a Time Warner Company. All rights reserved. (Photo: CNN)