China finds no clues to explain

China has found no clues to determine what caused a US government employee to suffer a brain trauma after experiencing unusual sounds, the foreign ministry said yesterday.

The US State Department has said the incident in the southern city of Guangzhou resembled the still-unexplained injuries that befell US and Canadian diplomats in Cuba last year.

"China has conducted a very careful investigation and has given preliminary findings to the US, and we haven't found the reason or clues that led to the situation mentioned by the US," foreign ministry spokesman Lu Kang told a regular press briefing.

"China has always followed the Vienna Convention on diplomatic relations and consular relations to protect the US diplomatic staff and staff from other countries," Lu said.

The US embassy in Beijing issued a health alert Wednesday over the incident, while saying it did not know what caused the symptoms or of any similar situations in the country.

The health alert said the employee "recently reported subtle and vague, but abnormal, sensations of sound and pressure".

The unidentified US citizen experienced a variety of physical symptoms between late 2017 and April 2018. The person was sent to the United States for further evaluation and on May 18 the embassy learned that the victim had mild traumatic brain injury (MTBI).