Chinese police cracked down four underground arsenals in the border areas of southwestern Chongqing Municipality, Hunan and Guizhou provinces on Friday morning, local authorities said.

Around one thousand armed police and public security officers joined in the clean-up action with the deployment of police helicopters and armored vehicles.

The massive raid began at 2:48 a.m. on Friday morning and ended at 4 a.m. Police said they seized dozens of suspects, but didn't give a specific number.