A member of nursing staff has been stabbed with a pair of scissors at a hospital A&E.
The 50-year-old woman suffered multiple stab wounds at Newham University Hospital in east London at about 05:39 BST.
Police said her injures were not life-threatening.
A 27-year-old man has been arrested on suspicion of grievous bodily harm and remains in custody at an east London police station.
Shane Degaris, deputy group chief executive of Barts Health NHS Trust, said it was a “shocking and senseless attack on a member of staff doing their duty”.
He said: “A member of nursing staff in the emergency department at Newham Hospital was stabbed by a member of the public while at work early this morning.
“The victim was treated in the emergency department, admitted to a ward and has since been discharged home.”
He added the trust was “reviewing security at all our hospitals to ensure the safety of all our staff and patients at all times”.