CHENGDU, March 6 -- Seven people remain missing after a minibus plunged into a lake in southwest China's Sichuan Province on Thursday morning, local police said.

The accident happened around 9:45 a.m. in Yilong County in the city of Nanchong when the 20-seat minibus carrying eight people veered off the road, broke the guardrail and plunged into Boyang Lake, according to the county's public security bureau.

Only the driver was rescued. The police are still searching for the missing people. An investigation into the cause of the accident is under way.