Yuandadu Relics Park, a popular gay hangout in Haidian District.

Hundreds of gay men have been rounded up and taken away in an ongoing police operation at Mudanyuan in Haidian district, Beijing.

About 20 police vehicles carrying four officers each including SWAT teams invaded the outdoor gay hangout Sunday night. Police hit the area again late last night.

"You can't imagine how deeply over 200 of us were wounded by this experience," one of the arrested gay men told the Global Times Monday on condition of anonymity.

He refused to discuss details of his treatment by the police.

They were taken to the Huayuanlu police station, revealed an online post on a website popular with Mudanyuan visitors. "They were required to show their identity cards, take a blood test, have their photo taken and leave their fingerprints."

The campaign was just part of the typical annual citywide public security inspection ahead of the National Day holiday, said Beijing Public Security Bureau spokesman Zi Xiangdong.

He did not elaborate what regulations had been violated by the seized men.