Dahni Ram Yadav, a rice miller and resident of Zaidpur area of neighbouring Ambedkarnagar district was admitted in Faizabad district hospital for treatment after he complained problem in his chest, police sources said.
He was being guarded by two armed police constables who at the time of incident were in the hospital.
The sources said three armed persons entered the hospital ward early this morning and opened fire at Dhani Ram Yadav from point blank range and fled away.
According to the police, constables Ajay Kumar and Raj Kumar, who were on guard duty with Dhani Ram Yadav, have been suspended.
Yadav was an accused in a murder case and is in Faizabad district jail since July 2011.
He was admitted to Faizabad district hospital on December 28.
Faizabad Circle Officer (City) Shashi Sekhar Singh said Yadav has received bullet injuries on the right side of his chest and he has been referred to a trauma centre in Lucknow.
"No one has given any statement about the incident. We are trying our best to catch the culprits