Baidu’s Apollo Go robotaxis experienced disruptions across Wuhan, China, with some passengers reportedly stranded for up to two hours, as outlined by several media sources along with a multitude of video and social media posts.

Baidu has yet to disclose the reason behind the extensive outage. Nevertheless, local police indicated it was a “system failure” impacting at least 100 robotaxis, as reported by Reuters. The unspecified technical malfunction led to robotaxis abruptly becoming unresponsive — and occasionally in perilous locations like the fast lane of highways, according to Wired. Authorities are continuing their investigation into the incident.

Baidu did not provide a response to TechCrunch’s emailed inquiry for comments.

Baidu is among the foremost robotaxi operators in China and has made strides into the Middle East. Last year, the firm announced its intention to roll out a fleet of over 1,000 autonomous vehicles in Dubai in the coming years.

The recent outage involving Baidu is the latest event to spark concerns about the safety of robotaxis and their effects on local populations. This issue extends beyond China as well; a significant power outage in California last December disabled traffic lights, causing Waymo vehicles to become immobilized.