(Reuters) -General Motors' Cruise co-founder and chief product officer Daniel Kan has resigned, the company told Reuters on Monday, a day after Cruise CEO Kyle Vogt quit.

A spokesperson for Cruise said Kan announced his resignation over a Slack message. The company offered no other details.

The new exit comes at a tumultuous time for self-driving taxi maker Cruise, which is undergoing a safety review of its U.S. fleet, which led Vogt to resign on Sunday.

Vogt, 38, offered little in the way of explanation, stating simply "I have resigned from my position" in an email to staff viewed by Reuters on Sunday.

Cruise's woes are also a setback for an industry dependent on public trust and the cooperation of regulators. The unit had in recent months touted ambitious plans to expand to more cities, offering fully autonomous taxi rides.

Vogt's resignation came after GM and the board at Cruise increased their scrutiny of its leadership.

(Reporting by Greg Bensinger in San Francisco; Editing by Chizu NomiyamaEditing by Chris Reese)