A 63-year-old man was fighting for his life after he was allegedly attacked with a hammer inside a major hospital in Sydney, Australia, on Thursday, police said.

Emergency services were called to the Royal Prince Alfred Hospital in Camperdown shortly after midnight on Thursday following reports of an assault in one of the wards.

Police alleged that a 46-year-old woman entered the hospital, asked staff for directions and later approached the bedside of the 63-year-old patient before attacking him.

The man suffered serious head injuries and was in critical condition, NSW police said. Authorities said they suspected the victim and the woman knew each other.

“The man remains in a critical condition,” the police said in a statement.

The woman was arrested at the scene, taken to the Newtown police station and charged with wounding a person with intent to cause grievous bodily harm.

She was refused bail and was expected to appear in court later on Thursday.

“Shortly after midnight this morning, a visitor coming in to see our patient attended the bedside of the patient and an unfortunate and serious event occurred,” Sydney health district chief executive Deborah Willcox said.

“I am advised the staff did speak to the person who came into the ward and there was no issue, to the best of my knowledge. “There was a conversation had between that person and the staff, and they went to the bedside of the patient,” Ms Willcox told reporters outside the hospital on Thursday.

“Our patient is well-known to the staff. Our primary interest is his well-being. The hospital ward had a number of other patients in our care.”

Ms Wilcox said that “no other patients were impacted”.

“We have attended to all of the patients in the ward just to debrief with them and make sure they’re OK. Everybody is OK,” she said.

Although the hospital had set visiting hours, Ms Willcox said, the buildings were accessible around the clock. “Our hospital is an open public building where people can gain access anytime of the day or the evening,” she pointed out. “We do whatever we can to enable people and visitors and friends and loved ones to see the patients.”