Five suspected robbers who were stranded in an ancient tomb in Shaanxi province had to call police for help, xinhuanet.com reported.

Two of the robbers were stranded nearly 20 meters deep in a subordinate tomb of a royal family of the Tang Dynasty (618-907), according to Sun Weidong, a police officer in Fuping county. It was dangerous, Sun said, as there was a shortage of oxygen and a risk of cave-ins.

Three rescuers carried oxygen tanks into the tomb. After more than an hour of searching, they spotted the suspects’ flashlight, and subsequently removed them from the tomb.

Fuping has many tombs of Tang Dynasty royal families.