Doctor and patient exchange gunfire at US hospital

An ambulance at the scene in Darby, Pennsylvania. Credit: APTN

A caseworker was killed after a psychiatric patient opened fire at a hospital wellness centre within a US hospital, officials have said.

Police said a doctor - who suffered a head wound in the incident - returned fire at the suspect using his own weapon in the psychiatric unit at Sister Marie Lenahan Wellness Center in Darby, Pennsylvania.

Officials added that the patient, named as Richard Plotts of Upper Darby, was critically wounded in the exchange of gunfire and is now in custody.

"They were able to, another doctor and another caseworker, were able to wrestle him to the ground, disarm him and at that point in time police actually arrived," Delaware County District Attorney Jack Whelan told the Associated Press news agency.