JOPLIN, Mo. (AP) — Law enforcement officers and a cybersecurity firm have been called in to investigate a “network security incident” that caused Joplin city government’s computer system to shut down, the city said Thursday.

The computer problem was discovered early Wednesday and the systems were not operating as of Thursday afternoon.

The affected system was isolated and investigators were called in, city spokeswoman Lynn Onstot said in a news release Thursday.

“As we investigate the incident and bring our systems back online, we will look for opportunities to further enhance our existing security measures,” she said.

The outage did not affect 911 emergency services, or the city’s ability to provide police, fire and emergency services, Onstot said.

However, the municipal court was not operating, online bill payments were inaccessible and some public transportation was not available.

Case investigations for communicable diseases through the city’s health department will be conducted on a limited basis until the issue is resolved, according to the release, but COVID-19 vaccinations were still available.

Other services such as the WIC program, temporary Medicaid applications, vital records, animal control dispatch also were available only on a limited basis.

The Joplin Municipal Airport was able to continue operating normally, the city said.