China's biggest ride-hailing company, Didi Chuxing, is suspending one of its services for the second time this year after a driver was accused of raping and killing a female passenger.

The company apologized for "disappointing mistakes" and said that two senior managers have been removed from their jobs following the death in the eastern coastal city of Wenzhou on Friday.

It is the second time in four months that Hitch, Didi's carpooling service, has been put on hold following the killing of a female passenger. The latest case fueled renewed outrage on Chinese social media, with users expressing fears about safety.

Police in Wenzhou said they arrested a Didi driver on Saturday morning, who confessed to raping and killing the passenger. The ministries of transport and public security summoned Didi executives for meetings Sunday, demanding a "comprehensive rectification" of the service, China's official news agency, Xinhua, reported.

Didi, one of the biggest startups in the world, drew global attention two years ago when it pushed Uber out of China. It has continued to expand, securing a valuation of $56 billion in December and making plays for more markets around the globe, including Australia and Mexico. Its investors include Apple (AAPL) and Japan's SoftBank (SFTBF).

Didi said in a statement that a complaint had been lodged about the driver the day before Friday's killing, but a customer service representative "failed to follow up with investigation within two hours," which is the company's policy.

The company said it is "deeply sorry" and continues "to work with the police and seek adequate settlement with the family" of the victim.

Messages asking for help

Police said the victim sent messages to one of her friends asking for help before she was killed. She was 20 years old and the suspect is 27, according to state media.

The killing exposed flaws in Didi's process for reporting issues with drivers, according to the company. It said it had removed Hitch's general manager and the vice president for customer services from their positions.

"The incident shows the many deficiencies with our customer service processes, especially the failure to act swiftly on the previous passenger's complaint and the cumbersome and rigid process of information sharing with the police, Didi said.

The driver passed an initial background check because he had no prior criminal record, and he logged on to the Hitch service with an authentic ID the day of the killing, according to the company. He also passed a facial recognition scan, but he "physically altered the appearance of his license plate" before the trip, it added.

The carpooling service, which has done more than 1 billion trips in the past three years, was shut down briefly in May after another female passenger was killed in Zhengzhou, a city in central China. The Didi driver suspected of killing her was later found dead, according to state media.

Didi then relaunched Hitch with some newly added safety features. The service allows passengers to catch rides from registered drivers headed in the same direction.

Hitch is one of a range of different app-based transportation services Didi operates in China, which also include shuttle buses, bike sharing and food delivery. The biggest part of its business is Didi Express, its main ride-hailing service, which dominates in terms of the number of rides.

Didi says it has roughly 550 million users, with around 30 million rides taking place every day through its platform.

-- Nanlin Fang, Angus Watson and Jethro Mullen contributed to this report.