Six nurses and one janitor were killed on Thursday morning in a dormity for female staff in 281 hospital in Beidaihe, Qinhuangdao city, North China's Hebei province.

One more nurse is injured with no life-threatening injuries.

The 27-year-old male suspect surnamed Li was taken into custody after the homicide was reported?to the police at 3:26 am local time.

Li said that he had mental diseases and was hospitalized for treatment in 2006.

Initial investigation didn't find direct conflicts between the suspect and the dead. Further investigate is still going on.

281 hospital is a sanatorium for Chinese PLA Beijing Military Region.