The official Xinhua news agency said China's deputy consul-general in the city and his family "were assaulted by US police while on their way back to China's consulate-general in Houston by car.”
"We noted the spokesperson of the US Department of State saying the US side takes this issue seriously and is investigating it," Chinese Foreign Ministry spokeswoman Jiang Yu said in a statement on the ministry's website (www.mfa.gov.cn).
"Protecting the safety of all foreign diplomatic and consular staff in the United States is essential," Jiang added.
China has lodged "solemn representations" with the United States about the incident, she said.
Beijing's relations with Washington have been strained recently over everything from the value of China's currency to US arms sales to Taiwan.
