China's top quality watchdog on Wednesday issued its second warning regarding potential safety hazards in U.S. automaker Chrysler's Jeep Wrangler vehicles, urging the company to fix the problem as soon as possible.

Overheated transmission systems have recently caused several fires in the vehicles, according to Li Yuanping, a spokesman with the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ).

AQSIQ previously issued a warning after suspending imports of Jeep Wranglers in April over the same problem.

From May this year, Chrysler began to recall 8,309 Jeep Wrangler vehicles sold on the Chinese mainland and offer free repairs for faulty transmission systems.

Although Chrysler has taken action to reduce overheating hazards, some risks still exist in related vehicle models, Li said.

AQSIQ urges car owners to contact local Chrysler dealers for repairs, while those who have already had their vehicles fitted with related devices against the overheating problem should be wary of risks that may still exist, he said.

Chrysler should find the root cause of the fires and fix the problem at its source, Li said.