After three years of separation from her parents in mainland China, Hong Kong resident Teresa Chow, originally from Zhejiang province, made sure she was among the first batch to cross the border.

"I'm so happy, so happy," said Chow, "My parents are not in good health and I couldn't go back to see them even when they had colon cancer."

All travelers were still required to test negative for COVID-19 via a PCR test within 48 hours prior to crossing, and passenger quotas apply to travel in both directions.