Xiaomi has confirmed that one of its SU7 electric vehicles, which are equipped with advanced driver assistance, was involved in an accident on an expressway in China.

Local media reported that three people died in the incident that’s likely to spark scrutiny over the smart driving software deployed in many of today’s cars.

The technology giant’s stock fell as much as 6.3% in Hong Kong before closing 5.5% lower. The shares have slumped almost 18% since Xiaomi raised about $5.5 billion in an equity sale last week to help fund an expansion of its EV business.