BEIJING (AP) — The staff of the Chinese consulate in Houston that was ordered shut by the U.S. government has returned to China.

Wearing face masks because of the coronavirus pandemic, they were greeted on the tarmac by Foreign Minister Wang Yi after disembarking from a chartered Air China flight in Beijing on Monday night.

“You have resolutely safeguarded the core interests, the dignity of the country and the legitimate rights of China’s overseas institutions under very difficult, even dangerous, conditions,” he said.

The U.S. abruptly ordered China to close the consulate last month, alleging it was the center of a network that collected intelligence, tried to steal intellectual property and harassed the families of Chinese dissidents while trying to coerce them to return to China.

Three days later, China ordered the U.S. consulate in Chengdu to close in retaliation. The tit-for-tat closures were seen as a significant escalation in the deterioration of ties between the two countries over a range of issues, including trade, technology, security and human rights.