In two separate and unrelated incidents on Tuesday night, seven nurses at hospitals in Shanghai and the southwestern city of Kunming were attacked by angry fathers upset at the way their children had been cared for - the latest in a series of confrontations underscoring tensions between medical staff and patients. In the attack in Shanghai, a nurse was left with a broken hand, and in Kunming, Yunnan, a nurse suffered a wound that required four stitches on her face. Police in the Minhang district of Shanghai said on their microblog that a man charged into a treatment room in the emergency ward of the Children's Hospital of Fudan University, then began insulting and attacking a nurse whom he accused of carelessly taking his child's blood. The father said the sample was not taken properly, causing it to solidify later and leaving it unfit for testing. It was not clear whether more blood was taken, or how the alleged mistake was made. Police said the father also fought off three other nurses who tried to calm him down. Three of the four nurses suffered minor injuries, while the other's hand was broken when it somehow became slammed in a door. The father, who was said to be a security guard at a shopping mall in the city, was detained by police. At almost the same time, another father became enraged at Kunming Children's Hospital, the Kunming.cn news portal reported. Police there said he fought a nurse and kicked her because he said a nurse had improperly inserted an intravenous tube into his child's foot, resulting in the foot swelling up. Three nurses, including the one attacked, fought the man until the hospital's security guards arrived. The hospital told the news portal that security footage exonerated the nurses, and they said the swelling began after the father carried his child out of a room where the tube was inserted. Local police were still investigating the incident. Dr Huang Cheng, who works at the Shanghai hospital, said the attack came as little surprise to him and his colleagues, as they too had faced confrontations with people in similar situations. 'Some [patients'] parents aren't well educated. Generally speaking, in our work, doctors are aware of patients' possibly becoming aggressive,' Huang said. 'There is a high turnover rate in our hospital.' There have been at least five incidents of violence directed at hospital doctors since last summer. In one of the most serious attacks, a woman doctor in Hengyang, Hunan province, died in late April after a patient slashed her neck. Another deadly attack occurred in March, when a young doctor in Harbin, Heilongjiang, was stabbed to death by a patient he had not treated.