The killing of a 21-year-old flight attendant in the central province of Henan last week has sparked heated debate on China’s active social media, fast becoming the most talked about topic on microblog platform Weibo with many expressing safety fears.

The case poses a challenge for Didi as it takes on rivals such as Uber Technologies Inc [UBER.UL] overseas. Didi’s backers include Apple Inc and Japan’s SoftBank Group Corp.

The company apologized and said it would suspend its Hitch service - a pooling service for passengers and drivers going to the same destination - from Saturday nationwide, and would start checks on drivers.

“Didi will suspend the Hitch service for a week nationwide for self-inspection and rectification,” it said in a statement.

Other services were not affected at Didi, the world’s largest ride-hailing firm by number of rides and a dominant player in China, where it has 450 million users.

Police in Zhengzhou, the provincial capital, are still hunting for the suspected killer of the victim, who had been traveling to the city from the airport hotel.

Didi said the male suspect had used a driver account that belonged to his father, who had passed the company’s verification process, criminal background screening and other security measures.

“The suspect borrowed his parent’s account to take orders, in violation of terms of our services,” the company said.

Didi said its facial recognition system, which matches the driver’s face with registration information, was not triggered before the suspect took the customer’s order.

The company said it would review drivers across all its services “to exclude any cases involving mismatch of drivers and vehicles”.

In 2016, Uber sold its Chinese operations to Didi in exchange for a stake of 17.5 percent in the Chinese firm, which also made a $1-billion investment in Uber.